But, though the teleology of instinct is wonderful in the extreme, the element of psychic regulation is so subordinate and restricted, that, far from postulating _intelligent_ control, certain scientists go so far as to deny even _sentient_ control, in the case of instinctive behavior. Animals, in their opinion, are nothing more than “reflex machines,” a view which coincides with that of Descartes, who regarded animals as unconscious automatons. “The instincts,” says Pawlow, “are also reflexes but more complex.” (_Science_, Nov. 9, 1923, p. 359.) The late Jacques Loeb was a protagonist of the view that instincts are simply _metachronic chain-reflexes_, in which one elementary process releases another, each preceding phase terminating in the production of the succeeding phase, until the entire gamut of concatenated arcs has been traversed. Hence, John B. Watson, the Behaviorist disciple of Loeb, defines instinct as “a combination of congenital responses unfolding serially under appropriate stimulation.” But, if Darwinian anthropomorphism sins by excess, Loeb’s mechanism sins by defect, and fails to account for the indubitable variability of instinctive behavior. For, however fixed and stereotyped such behavior may be, it manifests unmistakable adaptation to external circumstances and emergencies, as well as subordination to the general physiological condition of the organism, phenomena that exclude the idea of fatal predetermination according to the fixed pattern of a determinate series of reflex arcs. As Jennings has shown, synaptic coördination in the neural mechanism cannot be more than a partial factor in determining serial responses. The state of the organism as a whole must also be taken into account. (Cf. “Behavior of the Lower Organisms,” p. 251.) Thus an earthworm may turn to the right simply because it has just turned to the left, but this so-called “chain-reflex” does not involve an invariable and inevitable sequence of events, since the earthworm may turn twice or thrice to the left, before the second reaction of turning to the right comes into play. Any animal, when sated, will react differently to a food stimulus than it will when it is starved, by reason of its altered organic condition. We have something more, therefore, to reckon with than a mere system of reflexes released by a simple physical stimulus.