17. All these analysis of instinct are necessarily hypothetical and no one of them is sufficiently authentic in character to be given as a definite solution. The question will certainly be solved some day, when many will have attained to a power of observation revealing truths yet beyond our grasp. Until then it is necessary to submit these diverse opinions to the crucible of reason and logic, and wait until more light breaks. The solution which approaches the nearest to the truth will be necessarily that which harmonizes the best with the attributes of God; that is to say, to sovereign goodness and justice (see chap. II, n° 19).