Now if of the things we do there is an end which we wish for its own sake […] then clearly this end would be good and the highest good. Will not knowledge of it, then, have a great influence on our way of life, and would we not as a consequence be more likely to attain the desired end, like archers who have a mark to aim at? If so, then we should try to grasp, in outline at least, what that end is and to which of the sciences or faculties it belongs.

[εἰ δή τι τέλος ἐστὶ τῶν πρακτῶν ὃ δι᾽ αὑτὸ βουλόμεθα, τἆλλα δὲ διὰ τοῦτο, καὶ μὴ πάντα δι᾽ ἕτερον αἱρούμεθα （πρόεισι γὰρ οὕτω γ᾽ εἰς ἄπειρον, ὥστ᾽ εἶναι κενὴν καὶ ματαίαν τὴν ὄρεξιν）, δῆλον ὡς τοῦτ᾽ ἂν εἴη τἀγαθὸν καὶ τὸ ἄριστον. ἆρ᾽ οὖν καὶ πρὸς τὸν βίον ἡ γνῶσις αὐτοῦ μεγάλην ἔχει ῥοπήν, καὶ καθάπερ τοξόται σκοπὸν ἔχοντες μᾶλλον ἂν τυγχάνοιμεν τοῦ δέοντος; εἰ δ᾽ οὕτω, πειρατέον τύπῳ γε περιλαβεῖν αὐτὸ τί ποτ᾽ ἐστὶ καὶ τίνος τῶν ἐπιστημῶν ἢ δυνάμεων.]

Aristotle (384-322 BC) Greek philosopher

Nicomachean Ethics [Ἠθικὰ Νικομάχεια], Book 1, ch. 2 (1.2, 1094a.18ff) (c. 325 BC) [tr. Apostle (1975)]
    (Source)

(Source (Greek)). Alternate translations:

Since then of all things which may be done there is some one End which we desire for its own sake, [...] this plainly must be the Chief Good, i.e. the best thing of all. Surely then, even with reference to actual life and conduct, the knowledge of it must have great weight; and like archers, with a mark in view, we shall be more likely to hit upon what is right: and if so, we ought to try to describe, in outline at least, what it is and of which of the sciences and faculties it is the End.
[tr. Chase (1847)]

If then there be some one end of all that we do, for which we wish for its own sake [...] it is evident that this end will be the chief and supreme good. Surely then a scientific knowledge of it will have a critical influence upon our lives, and will make us, like bowmen who have a mark at which to aim, all the more likely to hit upon that which is good. And if this be so, we must endeavour to describe it at least in outline, and to say of what science or of what art it is the province.
[tr. Williams (1869)]

If it is true that in the sphere of action there is an end which we wish for its own sake [...] it is clear this will be the good or the supreme good. Does it not follow then that the knowledge of this supreme good is of great importance for the conduct of life, and that, if we know it, we shall be like archers who have a mark at which to aim, we shall have a better chance of attaining what we want? But, if this is the case, we must endeavor to comprehend, at least in outline, its nature, and the science or faculty to which it belongs.
[tr. Welldon (1892), ch. 1]

If then in what we do there be some end which we wish for on its own account, [...] this evidently will be the good or the best of all things. And surely from a practical point of view it much concerns us to know this good; for then, like archers shooting at a definite mark, we shall be more likely to attain what we want. If this be so, we must try to indicate roughly what it is, and first of all to which of the arts or sciences it belongs.
[tr. Peters (1893)]

If, then, there is some end of the things we do, which we desire for its own sake [...] clearly this must be the good and the chief good. Will not the knowledge of it, then, have a great influence on life? Shall we not, like archers who have a mark to aim at, be more likely to hit upon what is right? If so, we must try, in outline at least, to determine what it is, and of which of the sciences or capacities it is the object.
[tr. Ross (1908)]

If therefore among the ends at which our actions aim there be one which we will for its own sake [...] it is clear that this one ultimate End must be the Good, and indeed the Supreme Good. Will not then a knowledge of this Supreme Good be also of great practical importance for the conduct of life? Will it not better enable us to attain our proper object, like archers having a target to aim at? If this be so, we ought to make an attempt to determine at all events in outline what exactly this Supreme Good is, and of which of the sciences or faculties it is the object.
[tr. Rackham (1934)]

If, then, there is some end of things doable in action that we wish for because of itself, [...] it is clear that this will be the good -- that is, the best good. Hence regarding our life as well, won't knowing the good have great influence and -- like archers with a target -- won't we be better able to hit what we should? If so, we should try to grasp in outline, at least, what the good is and to which of the sciences or capacities it properly belongs.
[tr. Reeve (1948)]

So if what is done has some end that we want for its own sake [...] then clearly this will be the good, indeed the chief good. surely, then, knowledge of the good must be very important for our lives? And if, like archers, we have a target, are we not more likely to hit the right mark? If so, we must try at least roughly to comprehend what it is and which science of faculty is concerned with it.
[tr. Crisp (2000)]

If, therefore, there is some end of our actions that we wish for on account of itself, [...] clearly this would be the good, that is, the best. And with a view to our life, then, is not the knowledge of this good of greater weight, and would we not, like archers in possession of a target, better hit on what is needed? If this is so, then one must try to grasp, in outline at least, whatever it is and to which of the sciences or capacities it belongs.
[tr. Bartlett/Collins (2011)]