And if any man thinks that he knows anything, he knows nothing yet as he ought to know.
All Commentaries on 1 Corinthians 8:2 Go To 1 Corinthians 8
Cornelius a Lapide
AD 1637
And if any man think that he knoweth anything, he knoweth nothing yet as he ought to know. He who is puffed up at the thought that he knows something, knows not yet the end, use and measure of knowledge. Knowledge is given to cause humility, to enable us to benefit all that we can, to stand in the way of no one, to cause offence to no one, that so we may be known and loved by God. He is pointing at those who displayed their knowledge about the nature of idol sacrifices, by eating of them, though it were an offence to the untaught.
S. Bernard, in explaining this passage (Serm36 in Cantic.) says beautifully: "You see that he gives no praise to him that knoweth many things, if he is ignorant of the measure of knowing. That measure is to know the order, the zeal, and the end with which we should seek knowledge. The order is to seek that first which is more conducive to salvation. The zeal we should show is in seeking that more eagerly which makes us love more vehemently. The end of knowledge is not for vain glory, curiosity, or any like thing, but only for our own edification of that of our neighbour. For there are some who wish to know only that they may know, and this is vile curiosity. There are some who wish to know that they may be known themselves, and this is contemptible vanity: such do not escape the scoff of the satirist, "To know your own is nothing, unless another knows that you know yourself." There are some again who wish to know, that they may see their knowledge, and this is despicable chaffering. But there are also some who wish to know that they may edify, and this is charity; and some who with to know that they may be edified, and this is prudence. Of all these the last two only are not found to abuse knowledge, for they wish to gain understanding that they may do good." Again (de Conscientia, c. ii.) he says: "Many seek for knowledge, few conscience. If as much care and zeal were devoted to conscience as is given to the pursuit of empty and worldly knowledge, it would be laid hold of more quickly and retained to greater advantage."