Albert Barnes Commentary 1 Corinthians 12:15

"If the foot shall say, Because I am not the hand, I am not of the body; it is not therefore not of the body." — 1 Corinthians 12:15 (ASV)

If the foot shall say, etc. The same figure and illustration that Paul uses here also occurs in pagan writers. It occurs in the fable used by Menenius Agrippa, as related by Livy (Book 2, Chapter 32), in which he attempted to suppress a rebellion that had been incited against the nobles and senators, who were regarded as useless and cumbersome to the state.

Menenius, in order to show the folly of this, represents the different members of the body as conspiring against the stomach, accusing it of being inactive, refusing to labor, and consuming everything. The consequence of the conspiracy that the feet, hands, and mouth entered into was a universal wasting away of the whole frame, due to the lack of the nutriment that would have been supplied by the stomach.

Thus, he argued, it would be with the conspiracy against the nobles, who were seen as inactive and consuming all things. The representation had the desired effect and quelled the rebellion. The same figure is also used by Aesop. The idea here is that just as the foot and the ear could not claim they were not parts of the body, or even unimportant, simply because they were not the eye, etc. (that is, were not more honorable parts of the body), so no Christian, however humble their endowments, could claim to be useless because they were not more highly gifted and did not occupy a more elevated rank.