According to Osho, when a purely logical, rational mind reaches its pinnacle, it strips life of meaning by denying love, soul, and mystery. Logic is inherently destructive of meaning; it excludes love, which alone gives life joy and purpose. Deprived of love and wonder, the logical mind faces two 'logical' outcomes: suicide or madness. Hence he prescribes heart, love, and feeling.
Pursuing only logic kills love and mystery, making life feel pointless and pushing one toward giving up or breaking down.