The apparent incompatibility of mental states with physical explanations has long been a concern of philosophers of psychology. This incompatibility is thought to arise from the intentionality of mental states. But, Brentano notwithstanding, intentionality is an ordinary feature of higher order behavior patterns in the classical literature of ethology.
Thompson, Nicholas S., "The Intentionality of Some Ethological Terms" (1993). Faculty Works. 77.