Sec 307

In accordance with the distinction already taken, a legal incapacity resulting from the promisor's negligence, is no defence. Thus a railroad company which permits its power to purchase land to expire by legislative limitation, cannot set up such loss of power as a defence to a suit for the price of land it previously agreed to purchase.5

Sec 308

Casus is a disaster so extraordinary that its contingency would not be looked to by good business men in the particular specialty as something within the range of probability. As convertible with casus is frequently used the term "act of God." As "acts of God" are understood such extraordinary disturbances as "could not have been prevented by any amount of foresight and pains and care reasonably to be expected" from the party setting up this disturbance as excusatory.6 "Inevitable accident" is a term also used to express the same idea;7 but there are cases (e. g., unexpected interference of strangers, Legal impossibility induced by promisor's negligence no defence against which no reasonable prudence could guard) which might be called " inevitable accidents," but could not, in the ordinary sense of the words, be spoken of as "acts of God." It should be remembered, also, that the term " act of God" is used in a popular, and not in either a theological or a scientific sense. By a theist all things are regarded as coming more or less directly from God. By those rejecting belief in a supreme being, the term would be discarded altogether. In a scientific sense, also, the distinction is absurd, since all that science can deal with is government by law; and waiving the position that a government by law is far from excluding the idea of a supreme lawgiver, it cannot be supposed that there is any occurrence not explicable on the hypothesis of a system of order by which the equilibrium of the universe is maintained. But what concerns us more in the present issue is the fact that the term " act of God," as well as that of "inevitable accident," narrows with the gradual discovery of agencies by which catastrophies formerly supposed to be inevitable are now averted. One hundred years ago casus would be a good defence to an action against a carrier for a loss which had the telegram existed in those days, could have been readily averted by summoning aid which it would be negligence in the carrier now not to summon. One hundred years hence the domains of casus will be still further restricted. The question of casus, therefore, depends upon the diligence shown at the period in litigation by the party setting it up as a defence.1

Casus is a disaster which due diligence could not avert.

1 Ibid.; Leake, 2d ed. 695, 714.

2 Wh. Con. of Laws, sec 484.

3 Wh. Con. of Laws, sec 403, and cases there cited.

4 Infra, sec 311.

5 Hawkes v. R. R.. 1 D. M. & G. 737; aff. S. C, 3 De G. & S. 743.

6 James, L. J., Nugent v. Smith, 1 C. P. D. 423. See to same effect Nichols v. Marsland, 2 Ex. D. 1.

7 See Wh. on Neg. sec 553.

1 See authorities cited in Wh. on Neg. sec 114, 553; Carstairs v. Taylor, L. R. 6 Exch. 217; Street v. Holyoke, 105 Mass. 82; Gray v. Harris, 107 Mass. 492. "Accident," as a ground of equitable interference, is defined by Mr. Spence (1 Spence's Eq. 628) to be an unforeseen and injurious occurrence, not attributable to mistake, neglect, or misconduct; and this definition is approved by Mr. Bispham (Bisp. Eq. 174). To this, however, it may be objected that if "unforeseen" be taken in the wide sense, there would be few cases of accident in which equity could interfere, since there are few cases of accident whose contingency could not be in some sense foreseen. (See discussion in Wh. on Neg. sec 74 et seq.) In The Love Bird, 44 L. T. 650 (1881), it was held that under the English sailing rules of Sept. 1880, a loss which might have been prevented by the use of the mechanical fog-horn ordered by those rules, was imputable to the negligent ship.