Kafka warns against a subtler betrayal than outright conformity—the slow erosion that happens when we pre-emptively soften our edges to seem reasonable. Notice he pairs "logical" with "fashion," suggesting that even our appeals to rationality can be disguises we wear to appease others. A person who abandons a genuine creative vision because colleagues kept asking "but does it make practical sense?" has already bent before anyone forced them. The soul he means isn't the dramatic rebel's soul, but the particular, odd shape of who you actually are—which others will find difficult precisely *because* it refuses to arrange itself for their comfort.