Apostles of the Lord are our authorities: and even they did not choose to introduce anything of their own will, but faithfully consigned to the nations the instruction which they received from Christ. And so, even if an angel from heaven were to preach any other gospel, he would be called accursed by us" (_De Præs. Hær._, vi). In this passage, which contains a valuable comment on the meaning of the word "heresy," it will be noticed that Tertullian not only quotes the text before us as coming from the Epistle to Titus, but, like Irenæus, his earlier contemporary, says expressly that the words are those of St. Paul. Thus, from both sides of the Mediterranean, men who had very large opportunities of knowing what books were accepted as Apostolic and what not, attribute our Epistle without hesitation to St. Paul. And in both cases this is done in treatises directed against heretics, who might be expected to reply with very telling effect, if it could be shown that what was quoted against them as the writing of an Apostle was of quite doubtful origin and authority. But the testimony which these passages bear to the authenticity of this Epistle is not the main reason for their being quoted here. Their interest for us now consists in the light which they throw upon the history of the word "heresy," and upon the attitude of the primitive Church towards heretics. "Heresy," as Tertullian points out, is a word of Greek origin, and the idea which lies at the root of it is _choice_.[85] Choosing for oneself what pleases oneself, independently of other considerations;--that is the fundamental notion on which later meanings of the term are based. Thus in the Septuagint it is used of a _free-will_ offering, as distinct from what a man is bound to offer (Lev. xxii. 18; comp. 1 Macc. viii. 30). Then comes the notion of choice in reference to matters of opinion, without, however, necessarily implying that the chosen opinion is a bad one. And in this sense it is used quite as often for the party or school of thought which holds the particular opinion as for the body of opinion which is held. In this sense it is several times used in the Acts of the Apostles; as "the _sect_ of the Sadducees" (v. 17), "the _sect_ of the Pharisees" (xv. 5; xxvi. 5): and in this way Christianity itself was spoken of as a "heresy" or "sect"; that is, a party with chosen opinions (xxiv. 5, 14; xxviii. 22). And in profane literature we find Diogenes Laertius in the second or third century speaking of ten "heresies" or schools in moral philosophy (i. 19). But it will be seen from the passages in the Acts that the word is already acquiring somewhat of a bad meaning; and indeed this was almost inevitable, unless the original signification was entirely abandoned. In all spheres of thought and action, and especially in matters of belief, a tendency to choose for oneself, and to pursue one's own way independently, almost of necessity leads to separation from others, to divisions and factions.