Can we consider metaphysics part of philosophy? I found this paragraph in a letter written by Hermon von Helmholtz in 1902 that suggests that it is not.
“In my opinion nothing has been so pernicious to philosophy as its repeated confusion with metaphysics. The latter has played much the same part in relation to the former as that which astrology has been borne to astronomy. It has been metaphysics that turned the attention of the great majority of scientific amateurs to philosophy, and attracted troops of proselytes and disciples, who no doubt in many cases have wrought more harm than the bitterest opponents could have effected. They were led on by the delusive hope of obtaining insight, with little expenditure of time or trouble, into the deepest order of things and the nature of the human spirit, into the past and the future of the world – in which lay the main interest that incited so many to take up the study of philosophy, just as the hope of prognostications for the future formerly lead to the fostering of astronomy. What philosophy has so far been able to teach us, or with continued study of the facts involved, may one day be able to teach us, is of the utmost importance to the scientific thinker, who must know the exact capabilities of the instrument with which he is to work, that is, the human intellect. But as regards the satisfaction of this dilettante curiosity, or the still more frequent egoism of the individual, these serve and abstract studies will continue to yield only small and reluctant response: just as the mathematical mechanics of the planetary system and the calculations of perturbations are far less popular, despite their admirable systematic completeness, than was the astrological superstition of old days.”
“In my opinion nothing has been so pernicious to philosophy as its repeated confusion with metaphysics. The latter has played much the same part in relation to the former as that which astrology has been borne to astronomy. It has been metaphysics that turned the attention of the great majority of scientific amateurs to philosophy, and attracted troops of proselytes and disciples, who no doubt in many cases have wrought more harm than the bitterest opponents could have effected. They were led on by the delusive hope of obtaining insight, with little expenditure of time or trouble, into the deepest order of things and the nature of the human spirit, into the past and the future of the world – in which lay the main interest that incited so many to take up the study of philosophy, just as the hope of prognostications for the future formerly lead to the fostering of astronomy. What philosophy has so far been able to teach us, or with continued study of the facts involved, may one day be able to teach us, is of the utmost importance to the scientific thinker, who must know the exact capabilities of the instrument with which he is to work, that is, the human intellect. But as regards the satisfaction of this dilettante curiosity, or the still more frequent egoism of the individual, these serve and abstract studies will continue to yield only small and reluctant response: just as the mathematical mechanics of the planetary system and the calculations of perturbations are far less popular, despite their admirable systematic completeness, than was the astrological superstition of old days.”
