We may then venture to pronounce, with some degree of confidence, that man is provided by nature with a sense or faculty which lays open to him every passion by means of its external expressions. And I imagine that we cannot entertain any reasonable doubt of this fact, when we reflect, that even infants are not ignorant of the meaning of external signs. An infant is remarkably affected with the passions of its nurse expressed on her countenance: a smile chears it, and a frown makes it afraid. Fear thus generated in the infant, must, like every other passion, have an object. What is the object of this passion? Surely not the frown considered abstractly, for a child never abstracts. The nurse who frowns is evidently the object. Fear, at the same time, cannot arise but from apprehending danger. But what danger can a child apprehend, if it be not sensible that the person who frowns is angry? We must therefore admit, that a child can read anger in its nurse’s face; and it must be sensible of this intuitively, for it has no other means of knowledge. I have no occasion to affirm, that these particulars are clearly apprehended by the child. To produce clear and distinct perceptions, reflection and experience are requisite. But that even an infant, when afraid, must have some notion of its being in danger, is extremely evident. That we should be conscious intuitively of a passion from its external expressions, is conformable to the analogy of nature. The knowledge of this language is of too great importance to be left upon experience. To rest it upon a foundation so uncertain and precarious, would prove a great obstacle to the formation of societies. Wisely therefore is it ordered, and agreeably to the system of Providence, that we should have Nature for our instructor.