Apparent contradictions or differences occurring in the Gemara may be traced to the first cause and to the second, as e.g., “In this particular case he agrees with this rabbi”; or “He agrees with him in one point, but differs from him in another”; or “These two dicta are the opinions of two Amoraim, who differ as regards the statement made by a certain rabbi.” These are examples of contradictions traceable to the first cause. The following are instances which may be traced to the second cause. “Rabba altered his opinion on that point”; it then becomes necessary to consider which of the two opinions came second. Again, “In the first recension of the Talmud by Rabbi Ashi, he made one assertion, and in the second a different one.” The inconsistencies and contradictions met with in some passages of the prophetic books, if taken literally, are all traceable to the third or fourth cause, and it is exclusively in reference to this subject that I wrote the present Introduction. You know that the following expression frequently occurs, “One verse says this, another that,” showing the contradiction, and explaining that either some premise is wanting or the subject is altered. Comp. “Solomon, it is not sufficient that thy words contradict thy father; they are themselves inconsistent, etc.” Many similar instances occur in the writings of our Sages. The passages in the prophetical books which our Sages have explained, mostly refer to religious or moral precepts. Our desire, however, is to discuss such passages as contain apparent contradictions in regard to the principles of our faith. I shall explain some of them in various chapters of the present work; for this subject also belongs to the secrets of the Torah. Contradictions traceable to the seventh cause occurring in the prophetical works require special investigation; and no one should express his opinion on that matter by reasoning and arguing without weighing the matter well in his mind. Inconsistencies in the writings of true philosophers are traceable to the fifth cause. Contradictions occurring in the writings of most authors and commentators, such as are not included in the above-mentioned works, are due to the sixth cause. Many examples of this class of contradictions are found in the Midrash and the Agada; hence the saying, “We must not raise questions concerning the contradictions met with in the Agada.” You may also notice in them contradictions due to the seventh cause. Any inconsistency discovered in the present work will be found to arise in consequence of the fifth cause or the seventh. Notice this, consider its truth, and remember it well, lest you misunderstand some of the chapters in this book.