a prioriadv.adj.

1710 G. Berkeley Treat. Princ. Human Knowl. §21 I think arguments à posteriori are unnecessary for confirming what has been..sufficiently demonstrated à priori.

1771 J. Smeaton in Philos. Trans. (Royal Soc.) 61 210 Nor can we a priori determine the value of any new instrument.

1834 Penny Cycl. II. 199/1 In common language, we reason à priori when we infer the existence of a God from the general difficulties in the supposition of the existence of what we then call the creation on any other hypothesis; but we reason à posteriori when we infer the same from marks of intelligent contrivance in this particular creation with which we are acquainted.

1862 J. McCosh Supernat. ii. i. §2. 132 Reason commands us, in matters of experience, to be guided by observational evidence, and not by à priori principles.

1834 Penny Cycl. II. 199/1 When a sentence begins with ‘à priori we should think, etc. etc.’ [it] in most cases will be found to mean nothing more than an expression of the leaning which the speaker found his mind inclined to, when he had only heard the proposition, and before he had investigated it.

1882 F. W. Farrar Early Days Christianity I. 85 This, however, can have only been an à priori conjecture, and there is no evidence which can be adduced in its support.

1841 Sir W. Hamilton in Reid's Wks. 762/1 The term a priori, by the influence of Kant and his school, is now very generally employed to characterise those elements of knowledge which are not obtained a posteriori,—are not evolved out of experience as facticious generalizations; but which, as native to, are potentially in, the mind antecedent to the act of experience.