Reason is the servant of instinct.

Reason is progressive; instinct is complete; swift instinct leaps; slow reason feebly climbs.

Let him make use of instinct who cannot make use of reason

To live is like to love--all reason is against it, and all healthy instinct is for it.

Instinct ensures animals to have society. Reason ensures society to have animals.

In that way imagination and intelligence enter into our existence in the part of servants of the primary instincts