John Calvin Commentary James 2:17

"Even so faith, if it have not works, is dead in itself." — James 2:17 (ASV)

Is dead, being alone. He says that faith is dead, being by itself, that is, when lacking good works. We therefore conclude that it is indeed no faith, for when dead, it does not properly retain the name. The Sophists appeal to this expression, saying that some sort of faith is found by itself. However, this frivolous quibbling is easily refuted, for it is sufficiently evident that the Apostle reasons from an impossibility, just as Paul declares an angel anathema if he were to attempt to subvert the gospel (Galatians 1:8).