Of course the amount paid in respect of _lucrum cessans_ must be reasonable in regard to the loss of opportunity actually experienced; 'Lenders,' says Buridan, 'must not take by way of _lucrum cessans_ more than they would have actually made by commerce or in exchange';[1] and Ambrosius de Vignate explains that compensation must only be made for 'the time and just _interesse_ of the lost gain, which must be certain and proximate.'[2] [Footnote 1: _Eth._, iv. 6.] [Footnote 2: _De Usuris_, c. 10.] There was another title on account of which more than the amount of the loan could be recovered, namely, _periculum sortis_. In one sense it was a contradiction in terms to speak of the element of risk in connection with usury, because from its very definition usury was gain without risk as opposed to profit from a trading partnership, which, as we shall see presently, consisted of gain coupled with the risk of loss. It could not be lost sight of, however, that in fact there might be a risk of the loan not being repaid through the insolvency of the borrower, or some other cause, and the question arose whether the lender could justly claim any compensation for the undertaking of this risk. 'Regarded as an extrinsic title, risk of losing the principal is connected with the contract of _mutuum_, and entitles the lender to some compensation for running the risk of losing his capital in order to oblige a possibly insolvent debtor. The greater the danger of insolvency, the greater naturally would be the charge. The contract was indifferent to the object of the loan; it mattered not whether it was intended for commerce or consumption; it was no less indifferent to profit on the part of the borrower; it took account simply of the latter's ability to pay, and made its charge accordingly. It resembled consequently the contracts made by insurance companies, wherein there is a readiness to risk the capital sum for a certain rate of payment; the only difference was that the probabilities charged for were not so much the likelihood of having to pay, as the likelihood of not receiving back.'[1] [Footnote 1: Cleary, _op. cit._, p. 115.]