rudiment

(通例pl.)根本、基礎(原理)、(生)(器官が発達する以前の)原基

(noun) A fundamental element, principle, or skill, as of a field of learning. Often used in the plural.
(noun) Something in an incipient or undeveloped form. Often used in the plural: the rudiments of social behavior in children; the rudiments of a plan of action.
(noun) Biology An imperfectly or incompletely developed organ or part.

The capacity to ponder works of art and to say something which enlarges our conception of their value, or gives them a fresh relevance, is the rudiment of criticism as an art.