The immortality of the soul is a matter which is of so great consequence to us, and which touches us so profoundly, that we must have lost all feeling to be indifferent as to knowing what it is. All our actions and thoughts must take such different courses, according as there are or are not eternal joys to hope for, that it is impossible to take one step with sense and judgment, unless we regulate our course by our view of this point which ought to be our ultimate end.
Thus our first interest and our first duty is to enlighten ourselves on this subject, whereon depends all our conduct. Therefore among those who do not believe, I make a vast difference between those who strive with all their power to inform themselves, and those who live without troubling or thinking about it.
I can have only compassion for those who sincerely bewail their doubt, who regard it as the greatest of misfortunes, and who, sparing no effort to escape it, make of this inquiry their principal and most serious occupations.
But as for those who pass their life without thinking of this ultimate end of life, and who, for this sole reason that they do not find within themselves the lights which convince them of it, neglect to seek them elsewhere, and to examine thoroughly whether this opinion is one of those which people receive with credulous simplicity, or one of those which, although obscure in themselves, have nevertheless a solid and immovable foundation, I look upon them in a manner quite different.
This carelessness in a matter which concerns themselves, their eternity, their all, moves me more to anger than pity; it astonishes and shocks me; it is to me monstrous. I do not say this out of the pious zeal of a spiritual devotion. I expect, on the contrary, that we ought to have this feeling from principles of human interest and self-love; for this we need only see what the least enlightened persons see.
We do not require great education of the mind to understand that here is no real and lasting satisfaction; that our pleasures are only vanity; that our evils are infinite; and, lastly, that death, which threatens us every moment, must infallibly place us within a few years under the dreadful necessity of being for ever either annihilated or unhappy.