内ない因いん

noun

internal cause; intrinsic motivation

Used in medical, psychological, or philosophical contexts to refer to a cause originating from within a system or person, as opposed to an external cause (外因).

• 病びょう気きの内ない因いんと外がい因いんを区く別べつすることが重じゅう要ようだ。

  It is important to distinguish between internal and external causes of illness.

• 彼かれの行こう動どうの内ない因いんは、強つよい好こう奇き心しんにある。

  The intrinsic motivation behind his actions is a strong curiosity.