Beyond that there is nothing new to attempt in ethics. To admit only a single fact and to sacrifice to that all the rest,--such is the beaten way. Of all the facts that we have just analyzed, there is not one that has not in its turn played the part of sole principle. All the great schools of moral philosophy have each seen only one side of truth,--fortunate when they have not chosen among the different phases of the moral phenomenon, in order to found upon them their entire system, precisely those that are least adapted to that end! Who could now return to Epicurus, and, against the most manifest facts, against common sense, against the very idea of all ethics, found duty, virtue, the good, on the desire of happiness alone? It would be proof of great blindness and great barrenness. On the other hand, shall we immolate the need of happiness, the hope of all reward, human or divine, to the abstract idea of the good? The Stoics have done it,--we know with what apparent grandeur, with what real impotence. Shall we confine with Kant the whole of ethics to obligation? That is straitening still more a system that is already very narrow. Moreover, one may hope to surpass Kant in extent of views, by a completer knowledge and more faithful representation of facts; one cannot hope to be more profound in the point of view that he has chosen. Or, in another order of ideas, shall we refer to the will of God alone the obligation of virtue, and found ethics on religion, instead of giving religion to ethics as their necessary perfection? We still invent nothing new, we only renew the ethics of the theologians of the Middle Age, or rather of a particular school which has had for its adversaries the most illustrious doctors. Finally, shall we reduce all morality to sentiment, to sympathy, to benevolence? It only remains to follow the footsteps of Hutcheson and Smith, abandoned by Reid himself, or the footsteps of a celebrated adversary of Kant, Jacobi.[231] The time of exclusive theories has gone by; to renew them is to perpetuate war in philosophy. Each of them, being founded upon a real fact, rightly refuses the sacrifice of this fact; and it meets in hostile theories an equal right and an equal resistance. Hence the perpetual return of the same systems, always at war with each other, and by turns vanquished and victorious. This strife can cease only by means of a doctrine that conciliates all systems by comprising all the facts that give them authority. It is not the preconceived design of conciliating systems in history that suggests to us the idea of conciliating facts in reality. It is, on the contrary, the full possession of all the facts, analogous and different, that forces us to absolve and condemn all systems on account of the truth that is in each of them, and on account of the errors that are mixed with the truth.