The organic perfectibility or deterioration of the classes of the vegetable, or species of the animal kingdom, may be regarded as one of the general laws of nature.

This law extends itself to the human race; and it cannot be doubted that the progress of the sanative art, that the use of more wholesome food and more comfortable habitations, that a mode of life which shall develope the physical powers by exercise, without at the same time impairing them by excess; in fine, that the destruction of the two most active causes of deterioration, penury and wretchedness on the one hand, and enormous wealth on the other, must necessarily tend to prolong the common duration of man’s existence, and secure him a more constant health and a more robust constitution. It is manifest that the improvement of the practice of medicine, become more efficacious in consequence of the progress of reason and the social order, must in the end put a period to transmissible or contagious disorders, as well to those general maladies resulting from climate, aliments, and the nature of certain occupations. Nor would it be difficult to prove that this hope might be extended to almost every other malady, of which it is probable we shall hereafter discover the most remote causes. Would it even be absurd to suppose this quality of melioration in the human species as susceptible of an indefinate advancement; to suppose that a period must one day arrive when death will be nothing more than the effect either of extraordinary accidents, or of the slow and gradual decay of the vital powers; and that the duration of the middle space, of the interval between the birth of man and this decay, will itself have no assignable limit? Certainly man will not become immortal; but may not the distance between the moment in which he draws his first breath, and the common term when, in the course of nature, without malady or accident, he finds it impossible any longer to exist, be necessarily protracted? As we are now speaking of a progress that is capable of being represented with precision, by numerical quantities or by lines, we shall embrace the opportunity of explaining the two meanings that may be affixed to the word indefinite.

Through perpetual improvement through the sciences, humans may not ever attain immortality, but we may extend our lives indefinitely.

It is one of the most remarkable things that in all of the biological sciences there is no clue as to the necessity of death. If you say we want to make perpetual motion, we have discovered enough laws as we studied physics to see that it is either absolutely impossible or else the laws are wrong. But there is nothing in biology yet found that indicates the inevitability of death. This suggests to me that it is not at all inevitable, and that it is only a matter of time before the biologists discover what it is that is causing us the trouble and that that terrible universal disease or temporariness of the human's body will be cured. Anyhow, you can see that there will be problems of a fantastic magnitude coming from biology.

There is no law of biology that says things have to die.