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Part  5 The basic prerequisites for delictual liability

I.  Damage

A.The concept of damage

In Japan, which in principle does not have restitution in kind, the concept of dam- 7 / 215 age which is to be measured in money is discussed and described below:

1.Calculable damage – difference method ( Differenzmethode )

(   1  ) Pecuniary damage

These are firstly the pecuniary ( material ) disadvantages arising due to the tort. 7 / 219 They can further be divided into positive damage ( actual loss ) and negative dam-

age ( lucrum cessans ).

71Among the advocates of the Difference Method there are those who see the difference between the conditions of the interests as damage ( comparison of the actual conditions ), and those who see the difference between the respective sums of the assets as the damage ( monetary comparison ). In Japan, however, it is not always the case that a clear distinction is made between these two standpoints.

7 / 220 There is actual damage when the victim’s existing assets are actively reduced by the tort. If someone’s life or bodily integrity are injured, this may include expenses such as medical costs ( of treatment, hospital stays, caregiving, rehabilitation, etc ) as well as the costs of converting the victim’s home; when things are damaged, this may include repair costs or the expense of procuring a replacement. The reduction in the value of the damaged goods is also taken into account.

(  ii  ) Negative damage ( lucrum cessans )

7 / 221 Negative damage, on the other hand, is when it was to be expected that the victim’s assets would grow but this does not happen due to the tort. Lost profit falls into this category.

(   2  ) Non-pecuniary damage

7 / 222 Besides pecuniary damage, non-pecuniary damage can also arise as a result of the tort.

b.Assessment

7 / 223 In respect of the individual heads of damage, the following methods of assessment are applied.

(   1  ) Pecuniary damage

7 / 224 With respect to pecuniary damage, the difference is determined on the basis of the costs that really accrued and / or the amount that was really lost in respect of each head of damage. The underlying principle is the compensation of the actual damage.

(   2  ) Non-pecuniary damage

7 / 225 When it comes to non-pecuniary damage, on the other hand, there are no actual expenses or income to take as the basis; instead the assessment must be made at the judge’s discretion taking into account all relevant circumstances, including the gravity of the injury.

c.Problem issue

7 / 226 The following criticisms have been levelled at the difference method.

(   1  ) Methodological fuzziness

7 / 227 The theory is criticised for mixing the assessment of the damage in monetary terms with the determination and recoverability of the damage, leaving it unclear what has been determined in what manner.

(  ii  ) Harm not included in the heads of damage

If the damage is determined by adding together the individual heads of damage 7 / 229 and, in particular if the catalogue of damage is seen as fixed, it may also be the

case that damage is not included. While the difference method proceeds on the basis that the damage can be comprehensively determined, in reality a comprehensive assessment cannot be made.

2.Damage as actual damage

Nowadays, however, one influential view distinguishes between damage and dam- 7 / 230 age assessment and uses the expression » damage « only to refer to an actual state

but not the assessment of the harm suffered in money. Thus, a distinction is made between the determination that damage has occurred as well as – taking into account the protective scope – the recoverability of such, on the one hand, and the

assessment in money, on the other and these two steps are carried out consecutively72.

that, after being discharged from hospital, the victim had to go for rehabilitation for three months and had to pay the rehabilitation clinic; the fact that the victim is now confined to a wheelchair and had consequently to adapt his home and pay

72Hirai, Saiken kakuron II Fuhô kôi [ Obligation law Particular part II Tort ] 76.

73Maeda, Minpô IV-2 ( Fuhô kôi-hô ) [ Civil law IV-2 ( Law of torts ) ] ( 1980 ) 302 f.

7 / 233 In the case of damage to property, the following facts are examples of what may be regarded as damage: the fact that the victim’s motorbike had to be repaired in a garage as a result of the tort ( traffic accident ) and the victim had to pay for the repair costs; or the fact that the victim lost his motorbike as a result of the tort and had to buy a new one from a dealer.

(   2  ) Assessment

7 / 234 The amount of damages is assessed as follows using this approach.

(  i  ) Determination of the damage

7 / 235 Firstly, it is necessary as outlined above to determine a fact that constitutes damage. Thus, facts amounting to the ( cumulative ) heads of damage under the difference method are regarded as damage.

(  ii  ) Extent of the damages

7 / 236 Secondly, it is necessary to assess whether the facts amounting to damage determined above can be regarded as damage brought about by the infringement of a right. This corresponds to the examination under the difference method of whether there is an adequate causal link between the damage and the infringement of the right.

(  iii  ) Assessment in money

7 / 237 Thirdly, the facts amounting to damage which fall within the recoverable scope must be evaluated in monetary terms. This corresponds to the calculation of the difference in amount using the difference method.

(   3  ) Criticism

7 / 238 However, if concrete facts that correspond to the heads of damage are regarded as damage, it may happen that harm which cannot be identified in terms of such facts is not considered. Besides the case that the victim is injured by a tort but does not suffer any loss of income, regard must also be had to situations such as when a traumatised victim has in fact given up riding a motorbike due to an accident.

b.Comprehensive concept of damage

Nowadays nonetheless, among the ranks of the advocates of the actual damage 7 / 239 concept, a view that emphasises the purpose of restoring the original condition

and – in contrast to the above-described doctrine of concrete damage – categorises all harm brought about by the tort comprehensively as damage, has become influential.

bb.Assessment of damage

7 / 245 On this basis the concrete impairment of interest is calculated for each individual head of damage in line with the actual income and expenses.

(  ii  ) Exception

7 / 246 If, however, part of the damage cannot be taken into consideration within the framework of the individual heads of damage, this will be determined by free discretion via damages for pain and suffering.

b.Loss in value

7 / 247 On the other hand, it is argued that the reduction in the value of a right due to the infringement of the right constitutes damage. The question that arises here is at which level the value of the subjective right must be evaluated, ie whether the evaluation should be abstract or concrete.

(   1  ) Abstract value – death and bodily injury

7 / 248 One view taken is that, in the case of personal injury, death and bodily injury constitute damage and should be evaluated by a fixed amount as a standard type of damage. This is based above all on the equality of people and the dignity of the individual and on the principle that people cannot be seen as the source of pecuniary interests but as beings who have an inherent, equal value75.

(  i  ) Understanding of damage

7 / 249 This view understands the bodily injury or death of a person as ( non-pecuniary ) damage. If there is a causal link between the damaging conduct and the bodily injury or death ( this corresponds to causation as a prerequisite for liability ), then said bodily injury or death constitutes recoverable damage.

(  ii  ) Assessment of damage

7 / 250 The value lost due to death or bodily injury, ie the value of the life or body, is evaluated in each case by a fixed amount. This means, therefore, that the difference method is rejected as it relies on expenses actually incurred; in its place comes a standard fixed scale for the amount of compensation in accordance with the objective injury to the value of life or of bodily integrity.

75See ia Nishihara, Songai baishô no hôri [ Legal principles of the law of damages ], Jurisuto 381 ( 1967 ) 148.

This view sees the reduction of capacity to earn due to bodily injury as damage. 7 / 252 Even if in fact no difference has manifested with respect to the income and expenses accruing, the reduction of earning capacity as such is recognised as damage.

(  ii  ) Assessment of damage

Therefore, the value of the lost earning capacity is measured in money. Any stand- 7 / 253 ard sum in this respect is rejected as earning capacity is different for every victim.

2.Differentiation between infringement of a right and damage – normative concept of damage

Another view contends in this context that a distinction must be drawn between 7 / 254 infringement of a right and damage. According to this view, the question of which damage arose from the infringement of a right and to what extent this must be compensated must thus be examined separately from the causation giving rise to liability77.

76Kusumoto, Isshitsu rieki no santei no shotoku-gaku [ Calculation of lost profit and income ], in: Ariizumi ( ed ), Gendai songai baishô-hô kôza 7 [ Lectures on the modern law of damages 7 ] ( 1974 ) 133.

77Shiomi, Fuhô kôi-hô [ Law of tort ] 219 ff.

b.Gradation of the concept of damage

7 / 257 Nevertheless, the question is how to assess what the victim’s condition would have been in the absence of the damaging action.

(   1  ) Minimum damage – loss of value

7 / 258 As the minimum damage the value of the infringed right usually constitutes the recoverable damage.

(  i  ) Grounds – continuation of a right function ( Rechtsfortsetzungsfunktion ) of compensation

7 / 259 A claim to compensation due to an infringement of a right leads to compensation of the value in respect of the actual right. Therefore, the state that would have existed had the value of the right not been violated corresponds to state A ( condition of the victim as it would now be had there been no tort ).

(  ii  ) Determining the damage – abstract calculation of damage

7 / 260 In such a case the damage is determined by looking away from the actual concrete facts and estimating the value of the lost right, ie the value of life or bodily integrity or the value of a property right, in objective-abstract monetary terms.

(   2  ) Additional damage – impairment of individual interests

7 / 261 However, when it comes to impairment of an interest that rests on the individual circumstances of the victim and for which no compensation would be due pursuant to the above principles, additional compensation is granted besides the minimum damage.

(  i  ) Equation of determination of damage with determination of extent of damage

7 / 262 In this case the damage is seen as the sum of individual heads of damage in the sense of the method where the individual heads of damage are added together. For instance, with respect to expenses that were forced upon the victim due to the tort, the question of whether damage is recoverable is assessed based on the necessity of such expenses. As far as income that the victim could have earned is concerned had the tort not ensued, the question of whether this is recoverable damage depends on the probability of such income.

(  ii  ) Determination of the damage – concrete calculation of damage

7 / 263 The impairment of interest determined in line with the above is assessed in monetary terms with regard to the concrete circumstances.

C.Non-pecuniary damage and compensation for pain and suffering

The Japanese law of delicts sets no limit as to the types of recoverable damage. 7 / 264 Non-pecuniary damage is recognised as being recoverable as a matter of course.

This is usually compensated in the form of damages for pain and suffering.

1.Purpose of damages for pain and suffering

Nonetheless, there is controversy as to the purpose of damages for pain and suf- 7 / 265 fering.

a.Theory of restoration to the earlier state

to speak of such harm being compensated. Thus, instead it is only possible to see the damages as providing emotional satisfaction and thus restoration of the lost emotional balance.

b.Sanction and deterrence

81Mishima, Isha-ryô no honshitsu [ The nature of damages for pain and suffering ], Kanazawa Hôgaku 51–1 ( 1959 ) 1; Goto, Gendai songai baishô-ron [ Theory of the modern law of damages ] ( 1982 ) 255 ff; Awaji, Fuhô kôi-hô ni okeru kenri hoshô to songai no hyôka [ The legal protection within the law on unlawful conduct and the assessment of damage ] ( 1984 ) 156 f; Higuchi, Seisaiteki isha-ryô ron ni tsuite – Minkei shunbestu no » risô « to genjitsu [ On the theory of damages for pain and suffering as a sanction – » Ideal « and present state of the strict distinction between civil and criminal law ], Jurisuto 911 ( 1988 ) 19.

82Shiomi, Fuhô kôi-hô [ Law of tort ] 263 ff.

83Supreme Court of 11. 7. 1998, Minshû 51–6, 2573.

2.Calculation of the damages for pain and suffering

a.Concrete assessment

(  1   ) Procedure

7 / 283 The judge determines the damages for pain and suffering at his discretion; the circumstances that have been established in the oral hearing must be taken into consideration. The judge is not obliged to set out the grounds for his assessment in this respect84. On the other hand, neither does the victim have any duty of proof with respect to the amount of damages for pain and suffering85.

(   2  ) Circumstances that must be taken into account

7 / 284 The following circumstances must be taken into account when assessing the damages for pain and suffering.

(  i  ) Circumstances connected with the unlawful act

7 / 285 Firstly, the circumstances connected with the unlawful act must be taken into account. On the side of the victim, these include the conduct of the victim, whether there was fault on the part of the victim and the gravity of such. With respect to the injuring party, this refers to the purpose and motive for the unlawful act as well as the conduct ( intention, negligence, etc ).

(  ii  ) Circumstances regarding the parties

7 / 286 Secondly, the circumstances of the parties must be taken into account. Besides the age, profession and societal position of the victim and the injuring party, these include the financial situation and conduct of the injuring party.

b.Standard rates – fixed amounts for pain and suffering

7 / 287 For typical torts, such as road traffic accidents, there are guidelines for determining the damages for pain and suffering in standard cases, ie where there are no special circumstances86. When the main breadwinner of a family dies, these range between JPY 27 and 31 million, for example; when someone who is to be held equivalent to the main breadwinner is killed this is between JPY 24 and 27 million and in other cases between JPY 20 and 24 million.

84Cf ia Imperial Court of 5. 4. 1910, Minroku 16, 273; Imperial Court of 10. 6. 1914, Keiroku 20, 1157.

85Cf ia Imperial Court of 20. 12. 1901, Keiroku 7–11, 105.

86The reason why the sum is particularly high for death of a breadwinner is that the element of compensation for loss of support payments to the bereaved is included.

D.Damage through unwanted birth of a child

In Japan the question of damage due to the unwanted birth of a child has not yet 7 / 288 arisen in practice. Therefore, this problem has not yet been discussed separately

in Japan; instead there is only reference to the debate abroad.

II.  Causation

A.Concept of causation

1.General meaning of causation

Causation means that there is a cause and effect relationship between fact A and 7 / 289 fact B.

2.Relationship of cause and effect

However, it is questionable how a relationship of cause and effect is interpreted 7 / 290 with respect to the causation of a tort.

a.Difference between causation and limitation of imputation

meanwhile prevailing counter-view considers, however, that this makes the evaluation unclear and advocates examining these questions separately, specifically in three steps89.

87Wagatsuma, Jimu kanri, futô ritoku, fuhô kôi [ Negotiorum gestio, unjust enrichment and tort ] 154; Katô, Fuhô kôi [ Tort ] 152 ff.

88Imperial Court of 22. 5. 1926, Minshû 5, 386.

89See Hirai, Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 110. Thus, also Maeda, Minpô IV-2 ( Fuhô kôi-hô ) [ Civil law IV-2 ( Law of torts ) ] 126; Ikuyo / Tokumoto, Fuhô kôihô [ Law of tort ] 116 ff; Shinomiya, Fuhô kôi [ Tort ] 407; Shiomi, Fuhô kôi-hô I [ The law of tort I ]2 362 f, 386 f.

7 / 293 First it must be established whether the injuring action actually caused the result at issue ( infringement of a right or damage ) and thus, whether there is factually a causal relationship.

(  ii  ) Protective scope

7 / 294 The second step is a legal evaluation to examine whether the result ( infringement of a right or damage ) that is factually linked to the injuring act can be imputed to the injuring party.

(  iii  ) Assessment in money

7 / 295 The third step is to assess the damage that falls within the protective scope in monetary terms.

b.The nature of the causation test

7 / 296 This limits the examination of causation to the question of whether there is a factual causal link.

(   1  ) Evaluative assessment

7 / 297 It is generally recognised that this test is not a factual question in the sense of a natural sciences type test but necessarily includes an element of evaluation. The existence of a causal link is determined by reference to a regularity ( Gesetzmäßigkeit ) in that it is evaluated whether this regularity applies to a certain factual phenomenon or not. An evaluative element is inevitable in this context.

(   2  ) Factual aspect of the test

7 / 298 Nonetheless, it is ultimately an assessment of whether there is a factual causal relationship and, thus, it must be distinguished from the legal evaluation with respect to the protective scope.

B.Test

7 / 299 Causation generally means that there is a cause and effect relationship between fact A and fact B.

1.Test yardstick

7 / 300 How to determine whether there is a causal relationship between the injuring act and the result ( infringement of a right or damage ) is controversial.

a.Necessary condition

Traditionally, there was considered to be a factual causal link if one fact consti- 7 / 301 tuted a conditio sine qua non for the other fact90. This is based on the idea that the injuring party is also liable if there are several causes for a particular result consisting in an infringement of a right provided the injuring party’s act is a neces-

sary condition for the occurrence of said result.

b.A regularity

In contrast, however, one influential school of thought holds that the existence 7 / 302 of a factual causal link must be assessed according to whether, on the basis of a generally accepted regularity, it may be assumed that A is the cause of B91. This is

based on the idea that, insofar as there is a general persuasion as to what is the cause of result B, that is a regularity applies, it is sufficient to assess on this basis whether A is the cause of B.

2.Starting points for causation – cause and effect

Whichever school of thought one follows, both require that, in order to assess 7 / 303 whether there is a causal relationship, it is necessary that there is a fact ( A ), which

is the cause, and a fact ( B ), which is the result.

a.Cause – injuring party’s conduct

90Hirai, Saiken kakuron II Fuhô kôi [ Law of obligation Particular part II Tort ] 83.

91See Shiomi, Fuhô kôi-hô [ Law of tort ] 128; idem, Fuhô kôi-hô I [ The law of tort I ]2 350, 364. This builds on the German criminal law theory, in particular Engisch, Die Kausalität als Merkmal der strafrechtlichen Tatbestände ( 1931 ).

92Shinomiya, Fuhô kôi [ Tort ] 412 ff.

7 / 307 In such a case the causation must be recognised according to the formula of the necessary condition ( conditio sine qua non ): B would not have occurred, had A not happened. If the victim in the above example would not have been disabled, for example, were it not for the medical error, then causation must be recognised.

(   2  ) Omission

7 / 308 In the case of an omission, however, it is controversial whether a causal relationship is required.

(  i  ) No necessity for causation

7 / 309 On the one hand, it is argued that, in the case of omissions, no causation is conceivable and therefore a tort may be assumed regardless of a causal link93. This is because, in the case of an omission, an injuring party has in fact done nothing and, thus, there cannot be any conduct of A which may be regarded as the starting point for the causal relationship. This is why only the breach of the duty of conduct would be material, it is argued. However, this is a question of fault. This would mean that, in case of fault, liability should be recognised.

(  ii  ) Necessity of causation

7 / 310 On the other hand, it is also argued that, even in the case of an omission, it is definitely conceivable that there be a causal relationship and that delictual liability ought only to be recognised if such exists94.

aa.Starting point for a causal relationship

7 / 311 According to this view, the omission A, which offends against a duty of conduct ( » do A « ) is the starting point for the causal relationship. Thus, an omission that offends, for example, against the duty of conduct, » in order to diagnose liver cancer, carry out an effective examination «, ie if no effective examination has been conducted in order to recognise liver cancer, is the starting point for the causation test.

bb.Meaning of causation

7 / 312 According to the formula of the necessary condition, therefore, causation must be recognised in this case when B would not have happened had A been done. For example, if the victim would not have died had an effective examination to diagnose liver cancer been carried out, causation must be recognised95.

93Hirai, Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 83.

94Shinomiya, Fuhô kôi [ Tort ] 414; Sawai, Tekisutobukku jimu kanri, futô ritoku, fuhô kôi [ Textbook on negotiorum gestio, unjust enrichment and tort ]3 223; Shiomi, Fuhô kôi-hô I [ The law of tort I ]2 347 f.

95Supreme Court of 25. 2. 1999, Minshû 53–2, 235.

b.Result – infringement of a right

96Supreme Court of 22. 9. 2000, Minshû 54–7, 2574.

97Supreme Court of 22. 9. 2000, Minshû 54–7, 2574; Supreme Court of 11. 11. 2003, Minshû 57–10, 1466.

98However, much smaller amounts are awarded in this respect than are granted as compensation for the loss of life.

C.Competing causes

7 / 320 The issue becomes problematic, however, when several causes have brought about the result, specifically in the following two cases.

1.The competing cause is a force of nature

a.Problem issue

7 / 321 One case is when the unlawful act by the perpetrator competes as a cause with forces of nature. This problem arose, for instance, in the following situation: due to ongoing heavy rain there was a mudslide on a public street ( ie one built and administered by the state ). As the state did not notify citizens of this in time, however, a tourist bus with victim X on board continued along the street with no knowledge of the mudslide and had to stop when it got that far. The heavy rain caused another slide and the tourist bus was swept away and X killed.

(   1  ) Ground for liability

7 / 322 Since in this case the injuring party ( the state ) had not passed on information quickly enough and blocked the street, it is possible to speak of defectiveness with respect to the » construction and administration of a public construction « so that liability for a structure under art 2 para 1 State Redress Act may be applicable.

(   2  ) Legal interpretation

7 / 323 However, in this case there is not only a defectiveness in the construction and administration of a structure on the part of the injuring party ( the state ), natural forces ( mudslide due to heavy rains ) have also contributed to the occurrence of the relevant result ( infringement of a right or damage ). The question here is how this should be taken into account in respect of the prerequisites for and legal consequences of liability.

b.Causation

7 / 324 Firstly, it is controversial whether this can even be seen as a causation issue.

(   1  ) Quantitative understanding of causation – proportional causation

7 / 325 One view holds that when several causes have contributed to the occurrence of a result, the causation must be determined under consideration of the extent to

which each individual cause contributed99. Hence, causation is treated as a quantitative issue, namely how much each cause contributed to the occurrence of the result. If the proportionate contribution of the forces of nature ( eg 40 % ) is deducted, then the causal link between the defectiveness of the structure and the administration of the street and the result must be recognised in respect of the remaining share100.

(   2  ) Qualitative understanding of causation

Generally, however, it is assumed that there is causation if B would not have hap- 7 / 326

pened had it not been for A, so that the causal link is either determined to exist or not101.

c.Not a causation issue

If causation is understood in the second sense, then the problem must be ap- 7 / 327 proached from a different perspective102. The following possibilities are among

the available options.

(   1  ) Prerequisites for liability – existence of negligence or a defect

On the one hand, it would be possible that the issue be considered when assess- 7 / 328 ing whether the injuring party was negligent and whether there was defectiveness

in the construction or administration of the public structure. In the sample case above, the question would be whether the injuring party was obliged to prevent such consequences as were brought about by the forces of nature ( infringements of rights and damage ) and / or to undertake precautions against such grave consequences of the natural forces ( infringements of rights and damage ).

99Nomura, Inga kankei no honshitsu – kiyo-do no motozuku waraiteki inga kankei-ron [ The nature of causation – theory of proportional causation independent of the extent of the share ], in: idem, Kôtsû jiko songai baishô no hôri to jitsumu [ Legal principles and practice of the law of damages with respect to road traffic accidents ] ( 1984 ) 62 ff.

100District Court Nagoya of 30. 3. 1973, Hanrei Jihô 700, 3.

101On proportional causation, see in detail Kubota, Kashitsu sôsai no hôri [ Legal theory of contributory fault ] ( 1994 ) 87; Yoshimura, Kôgai, kankyô shihô no tenkai to konnichiteki kadai [ The development of private law on the environment and the law of environmental damage and its present-day tasks ] ( 2002 ) 316 f.

102Hirai, Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 85 ff; Sawai,   Tekisutobukku jimu kanri, futô ritoku, fuhô kôi [ Textbook on negotiorum gestio, unjust enrichment and tort ]3 224 f; Yoshimura, Fuhô kôi [ Tort ]4 101 f; Shiomi, Fuhô kôi-hô I [ The law of tort I ]2 370 f.

(   2  ) Consequences of liability – determining the amount of compensation

7 / 329 On the other hand, this issue could be considered when it comes to determining the amount of compensation due. The question in this respect would be whether the amount of compensation should be diminished owing to the role played by the forces of nature.

2.Other injuring acts as competing causes

7 / 330 Another case is when, besides the injuring party’s tort, there were other tortious acts that come into question as the cause of the result ( infringement of a right or damage ). An example of this would be when both factory Y1 and factory Y2 release sewage into a river and the fish farm downriver that belongs to X is destroyed as a result.

7 / 332 Firstly, several causes may compete with each other but all also have had the potential to bring about the result on their own. In the above case this would be true if both the sewage from Y1 and the sewage from Y2 would have been sufficient to kill X’s fish.

(   1  ) Conditio sine qua non

7 / 333 If causation is understood in the sense of the conditio sine qua non formula, the consequences are as follows104.

(  i  ) Conditio sine qua non

7 / 334 If the formula of the conditio sine qua non is applied directly, then the fish would also have died had Y1 not released its sewage into the river; therefore there is no causal link.

(  ii  ) Exceptions

7 / 335 However, it would be unfair if someone who actually ought to be liable alone is released from liability simply because, as chance would have it, another injuring act also took place. Therefore, it is accepted that this case is to be considered an

103As in both cases cited below there is a causal link, the question of the extent of compensation also arises.

104Hirai, Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 84; Yoshimura, Fuhô kôi [ Tort ]4 102.

D.Proof of causation

1.Standard of proof

With respect to the proof of causation, the question as to standard of proof arises, 7 / 340 ie what degree of proof is necessary in order to persuade the judge when consider-

ing the evidence, the following view is generally presented107.

105See eg Shiomi, Fuhô kôi-hô I [ The law of tort I ]2 368.

106Hirai, Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 84 ff; Shinomiya, Fuhô kôi [ Tort ] 423 ff.

107Supreme Court of 24. 10. 1975, Minshû 29–9, 1417; Supreme Court of 16. 6. 2006, Minshû 60–5, 1997.

a.High probability

7 / 341 High probability that a certain fact brought about a certain result must be proven to establish causation.

(   1  ) No necessity for actual scientific proof

7 / 342 According to this view, it is not required that actual scientific proof be produced to the effect that absolutely no doubt is allowed.

(   2  ) Simple probability is not sufficient

7 / 343 Simple probability, however, is not enough. It is considered that, if the court was to form its opinion on the basis of simple probability, this would endanger the public’s trust in the fact-finding of the court.

b.Yardstick for evaluating probability

7 / 344 There is high probability if an average person can be persuaded of the truth of the case without doubt. Requiring that everybody has to be convinced without any doubt whatsoever would ask the impossible of the court and the parties.

2.Burden of proof

7 / 345 Further, there is the question of which party has the burden of proof as regards causation, ie whose risk it is if the causation is not provable ( non liquet ).

a.Basic rule

7 / 346 In principle, the victim bears the burden of proof as regards causation, for the following reasons:

7 / 347 The principle that the owner of the right must bear the infringements to his rights himself applies in principle. The law of delicts makes it possible, however, to shift this damage to the injuring party. The necessary prerequisites in this respect must therefore be proven by the owner of the right, ie the victim.

b.Exception

7 / 348 Nonetheless, the victim is aided in the case of evidentiary difficulties by the following means.

(   1  ) Reversal of the burden of proof

7 / 349 Firstly, the duty to prove that there is no causal link may be shifted to the injuring party. This is the case in the following situations:

108Art 719 para 1 CC states: » If more than one person has inflicted damage on others by their joint tortious acts, each of them shall be jointly and severally liable to compensate for this damage. The same shall apply if it cannot be ascertained which of the joint tortfeasors inflicted the damage «. Although sent 2 refers to » joint tortfeasors «, there does not need to be any particular connection between all the perpetrators according to prevailing opinion today, because sent 1 already applies if such a connection exists. See eg Shinomiya, Fuhô kôi [ Tort ] 792 ff; Hirai,   Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 199.

7 / 357 If, in cases of environmental damage, the cause of the illness or the causal substance ( A ) and the means of pollution ( B ) are proven and if the source of the pollution reaches » to the doors of the enterprise «, then it is presumed that the toxins and emissions ( C ) derive from there, insofar as the entrepreneur cannot prove why his factory cannot be the source of the pollution109. This relates to prima facie evidence based on the rule of experience that if there is A and B, in general C can be assumed.

bb.Epidemiological causation

7 / 358 Furthermore, it is possible to observe the reason for a group of people being ill and to explain it and on this basis to establish the individual causation for each individual and their illness. This is known as epidemiological causation110.

(   3  ) Prerequisites

7 / 359 In general there are four prerequisites for recognising epidemiological causation. Firstly, that the factor operates for a certain time before the illness breaks out; secondly, that the stronger this factor is, the higher the rate of people falling ill; thirdly, that the special features of the progress of the illness can be explained without any contradiction on the basis of the spread of the factor; and fourthly, that the mechanisms of how this factor operates can be explained as the cause without any biological contradictions.

(   4  ) Significance

7 / 360 Epidemiological causation is actually causation in respect of a whole group. It is not ensured separately that this applies to causation in respect of the individual victims within this group. However, epidemiological causation is understood as a kind of rule of experience, according to which, when the victim belongs to a certain

109District Court Niigata of 29. 9. 1971, Hanrei Jihô 642, 96 ( Niigata Minamata case of illness ).

110District Court Tsu, branch Yotsukaichi of 24. 7. 1972, Hanrei Jihô 672, 30 ( Yotsukaichi asthma case ). In detail on this, eg Yoshimura, Fuhô kôi [ Tort ]4 106 f; Shiomi, Fuhô kôi-hô I [ The law of tort I ]2 377.

group ( A ), in general it is possible to assume the causal link ( B )111. Thus, if the victim proves A, then it is up to the injuring party to show that epidemiological causation does not apply in respect of this particular victim by proving special circumstances, in order to establish the non-provability ( non liquet ) of the causal link. This is the practical significance of epidemiological causation.

111Shinomiya, Fuhô kôi [ Tort ] 410 ff; Hirai, Saiken kakuron II Fuhô kôi [ Law of obligations Particular part II Tort ] 89 f; Yoshimura, Fuhô kôi [ Tort ]4 108.