After this sorrow, his daughter, Mrs. Carmichael, lived much in his house in the Professors’ Court. She became a widow in the same year, for her husband died a few months after Mrs. Reid. Elizabeth Leslie, daughter of his stepsister Margaret, was also an inmate, and added to the comfort of the closing years. Soon after her father’s death Mrs. Carmichael went to live at Aberdeen. CHAPTER VIII INSPIRED COMMON SENSE AND CAUSATION: ACTIVE OR MORAL POWER IN MAN Philosophical recognition of the genuine Common Sense or natural judgment of mankind, especially in two of its factors, which seemed to Reid obscured if not suppressed by dogmatic hypothesis, gave its character to his whole intellectual life. He found, in the first place, that ‘all philosophers; from Plato to Mr. Hume, agree in this, that we do not perceive external objects immediately, and that the immediate object of perception must be some image present to the mind.’ To rid philosophy of this hypothesis, as a mere prejudice, inconsistent with the absolute trustworthiness, and therefore with the supreme and final rational authority of our natural judgment, was the chief aim of his Aberdonian life—culminating in the _Inquiry_ in 1764. He found, in the second place, that ‘to confound the notion of agent or efficient cause with that of physical cause has been a common error of philosophers, from the days of Plato to our own’; and it seemed to him as subversive of moral relations in the universe as the other was of physical relations. Accordingly, our conception of Power or Causation chiefly engaged him in Glasgow. This appears in his ‘Essays’ on moral Power in man; in his correspondence with Kames and Gregory in the last twenty years of his life; as well as in the unpublished fragment on ‘Power,’ in 1792, which was his last expression of reflective thought. The Philosophy of Perception and the Philosophy of Causation—our common sense of extended reality in our first intercourse with it in the senses, and our common sense conception of ‘power’ and ‘cause’ which arises in the presence of the changes amidst which we live and have our being—these were the two poles of Reid’s philosophical life. His whole life was a war against two common errors of philosophers regarding these, from the days of Plato to our own, in each of which the seeds of speculative and practical scepticism seemed to lie thickly. If these two fundamental convictions were untrustworthy, then faith in anything must lose its sustaining strength. For our perceptions through the five senses are the first principles of all our reasonings about the actual universe, and our causal judgments are the means of interpreting the realities to which those perceptions only introduce us.