440

index by country

Spain (cont.)

unilateral contract 36

promise to sell at fixed price, whether

definition/requirements 36;

binding in case of change of market

common/civil law distinguished 36

price (cont.)

offer, acceptance, need for 36–7

unforeseen circumstances theory and

promise to sell, revocability,

202

motivation, relevance 29

proportionality, services rendered,

unilateral promise to sell (promesse

promise of remuneration 74

unilatérale de vente)

real property transaction, registration,

as option contract (contrat de promesse)

need for 286

286–7

services rendered [without charge],

changed circumstances 287

promise to pay remuneration for

pacta sunt servanda and 287

as natural obligation 73–4, 84–5, 358–9

waiver of right, consideration, relevance

as onerous contract 74

270–1, 277

as remunatory donation 74, 359; causa

donandi 244, 252; definition 87;

United States

requirements, writing 74; status of

consideration/cause

parties, relevance 74; sum above

circumvention of rule by courts,

usual level 74

detrimental reliance on promise

legal formalities/requirements 74

and, Restatement of Contracts (First and

servicio amistoso 156

Second) 12

social engagement, agreement to keep,

estoppel and 13

as, contract, writing, need for 108,

estoppel

116

consideration and 13

specific performance

requirements, pre-existing legal rights

contract of agency 156

363

contract of deposit/promise to store

moral consideration 82

goods without charge 126, 145; in

Restatement of Contracts (First) 12, 13

absence of contract 145; contractual

Restatement of Contracts (Second) 12, 13, 359

obligation 127

services rendered [without charge],

contract/promise of loan for use 179

promise to pay remuneration for,

option contract (contrat de promesse) 286

enforceability, unjust enrichment

sums exceeding usual or obligatory level

and, Second Restatement of Contracts

or financial means, treatment as gift

359

or remunatory donation, services

unjust enrichment, services previously

rendered without charge 74

rendered without charge, Restatement

teoria de la base del negocio 202–3, 215

of Contracts (Second) 359