Aristotle, Nicomachean Ethics
H. Rackham, Ed.

Let this account then serve to describe the Good in outline—for no doubt the proper procedure is to begin by making a rough sketch, and to fill it in afterwards. If a work has been well laid down in outline, to carry it on and complete it in detail may be supposed to be within the capacity of anybody; and in this working out of details Time seems to be a good inventor or at all events coadjutor. This indeed is how advances in the arts have actually come about, since anyone can fill in the gaps. [18] Also the warning given above² must not be forgotten; we must not look for equal exactness in all departments of study, but only such as belongs to the subject matter of each, and in such a degree as is appropriate to the particular line of enquiry. [19] A carpenter and a geometrician both try to find a right angle,³ but in different ways; the former is content with that approximation to it which satisfies the purpose of his work; the latter, being a student of truth, seeks to find its essence or essential attributes. We should therefore proceed in the same manner in other subjects also, and not allow side issues to outbalance the main task in hand.