Seneca quote

From Moral letters to Lucilius - Letter 59 (Kindle):

We human beings are fettered and weakened by many vices; we have wallowed in them for a long time and it is hard for us to be cleansed. We are not merely defiled; we are dyed by them. But, to refrain from passing from one figure to another, I will raise this question, which I often consider in my own heart: why is it that folly holds us with such an insistent grasp? It is, primarily, because we do not combat it strongly enough, because we do not struggle towards salvation with all our might; secondly, because we do not put sufficient trust in the discoveries of the wise, and do not drink in their words with open hearts; we approach this great problem in too trifling a spirit. But how can a man learn, in the struggle against his vices, an amount that is enough, if the time which he gives to learning is only the amount left over from his vices? None of us goes deep below the surface. We skim the top only, and we regard the smattering of time spent in the search for wisdom as enough and to spare for a busy man. What hinders us most of all is that we are too readily satisfied with ourselves; if we meet with someone who calls us good men, or sensible men, or holy men, we see ourselves in his description, not content with praise in moderation, we accept everything that shameless flattery heaps upon us, as if it were our due. We agree with those who declare us to be the best and wisest of men, although we know that they are given to much lying. And we are so self-complacent that we desire praise for certain actions when we are especially addicted to the very opposite. Yonder person hears himself called "most gentle" when he is inflicting tortures, or "most generous" when he is engaged in looting, or "most temperate" when he is in the midst of drunkenness and lust. Thus it follows that we are unwilling to be reformed, just because we believe ourselves to be the best of men.