103.  In the next place there was my care, my duty, the hoar hairs and weakness of my holy parents, who were more greatly distressed on my account than by their advanced age—of this Patriarch Abraham whose person is honored by me, and numbered among the angels, and of Sarah, who travailed in my spiritual birth by instructing me in the truth.  Now, I had specially pledged myself to become the stay of their old age and the support of their weakness, a pledge which, to the best of my power, I have fulfilled, even at the expense of philosophy itself, the most precious of possessions and titles to me; or, to speak more truly, although I made it the first object of my philosophy to appear to be no philosopher, I could not bear that my labor in consequence of a single purpose should be wasted, nor yet that blessing should be lost, which one of the saints of old is said to have stolen from his father, whom he deceived by the food which he offered to him, and the hairy appearance he assumed, thus attaining a good object by disgraceful trickery. Gen. xxvii. 21, sq.  These are the two causes of my submission and tractability.  Nor is it, perchance, unreasonable that my arguments should yield and submit to them both, for there is a time to be conquered, as I also think there is for every purpose, Eccles. iii. 1. and it is better to be honorably overcome than to win a dangerous and lawless victory.