our eyes nor abstain from straight speech; but neither do we tire in working with our whole soul and body worthily to return worthy service to the beneficent God. Nor do we make full return save that we slacken not in that which is entrusted to us; but we fill full the measures of our opportunity and without envy communicate to all whatsoever the Holy Spirit shall provide. Thus we not only bring into the open by refutation the affairs of the enemy;[13] but also whatever the truth has received by the Father’s grace and ministered to men. These things we preach[14] as one who is not ashamed, both interpreting them by discourse and making them to bear witness by writings. In order then, as we have said by anticipation, that we may show these men to be godless alike in purpose, character and deed, and from what source their schemes have come--and because they have in their attempts taken nothing from the Holy Scriptures, nor is it from guarding the succession of any saint that they have been hurried into [Sidenote: p. 6.] these things, but their theories[15] take their origin from the wisdom of the Greeks, from philosophizing opinions,[16] from would-be mysteries and from wandering astrologers--it seems then proper that we first set forth the tenets of the philosophers of the Greeks and point out to our readers[17] which of them are the oldest and most reverent towards the Divinity.[18] Then, that we should match[19] each heresy with a particular opinion so as to show how the protagonist of the heresy, meeting with these schemes, gained advantage by seizing their principles and being driven on from them to worse things constructed his own system.[20] Now the undertaking is full of toil and requires much research. But we shall not be found wanting. For at the last it will give us much joy, as with the athlete who has won the crown with much labour, or the merchant who has gained profit after great tossing of the sea, or the husbandman who gets the benefit of his crops from the sweat of his brow, or the prophet who after reproaches and insults sees his predictions come to pass.[21] We will therefore begin by declaring which of the Greeks first made demonstration of natural philosophy. For of them especially have the protagonists of the heretics become the plagiarists, as we [Sidenote: p. 7.] shall afterwards show by setting them side by side. And when we have restored to each of these pioneers his own, we shall put the heresiarchs beside them naked and unseemly.[22] 1. _Thales._