 He believed that moral knowledge is gained via our moral sense. A sense, as the term is deployed by Hutcheson, is every determination of our minds to receive ideas independently of our will, and to have perceptions of pleasure and pain. In accordance with this definition, the five external senses determine us to receive ideas which please or pain us, and the will does not intervene — we open our eyes and by natural necessity see whatever it is that we see. But Hutcheson thought that there were far more senses than the five external ones. Three in particular play a role in our moral life. The public sense is that by which we are pleased with the happiness of others, and are uneasy at their misery. The moral sense is that by which we perceive virtue or vice in ourselves or others, and derive pleasure, or pain, from the perception. And the sense of honour is that which makes the approbation, or gratitude of others, for any good actions we have done, the necessary occasion of pleasure. In each of these cases the will is not involved. We see a person acting with the intention of bringing happiness to someone else, and by the frame of our nature pleasure wells up in us.