THERE is no method of reasoning more common, and yet none more blameable, than, in philosophical disputes, to endeavour the refutation of any hypothesis, by a pretence of its dangerous consequences to religion and morality. When any opinion leads to absurdities, it is certainly false; but it is not certain that an opinion is false, because it is of dangerous consequence. Such topics, therefore, ought entirely to be forborne; as serving nothing to the discovery of truth, but only to make the person of an antagonist odious.
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Of Liberty and Necessity, Part II (http://www.bartleby.com/37/3/12.html)David Hume
The discovery of truth is prevented more effectively, not by the false appearance things present and which mislead into error, not directly by weakness of the reasoning powers, but by preconceived opinion, by prejudice.
Arthur Schopenhauer
In all determinations of morality, this circumstance of public utility is ever principally in view; and wherever disputes arise, either in philosophy or common life, concerning the bounds of duty, the question cannot, by any means, be decided with greater certainty, than by ascertaining, on any side, the true interests of mankind. If any false opinion, embraced from appearances, has been found to prevail; as soon as farther experience and sounder reasoning have given us juster notions of human affairs, we retract our first sentiment, and adjust anew the boundaries of moral good and evil.
David Hume
The very attempt to determine the relationship of a philosophical work to other efforts concerning the same subject, introduces an alien and irrelevant interest which obscures precisely that which matters for the recognition of the truth. Opinion considers the opposition of what is true and false quite rigid, and, confronted with a philosophical system, it expects agreement or contradiction. And in an explanation of such a system, opinion still expects to find one or the other. It does not comprehend the difference of the philosophical systems in terms of the progressive development of the truth, but sees only the contradiction in this difference. The bud disappears as the blossom bursts forth, and one could say that the former is refuted by the latter. In the same way, the fruit declares the blossom to be a false existence of the plant. These forms do not only differ, they also displace each other because they are incompatible. Their fluid nature, however, makes them, at the same time, elements of an organic unity in which they not only do not conflict, but in which one is as necessary as the other; and it is only this equal necessity that constitutes the life of the whole.
Georg Wilhelm Friedrich Hegel
'Tis a dangerous thing to engage the authority of scripture in disputes about the natural world, in opposition to reason; lest time, which brings all things to light, should discover that to be evidently false which we had made scripture to assert … We are not to suppose that any truth concerning the natural world can be an enemy to religion; for truth cannot be an enemy to truth, God is not divided against himself.
Thomas Burnet
He will better comprehend the foundations and measures of decency and justice, and have livelier, and more lasting impressions of what he ought to do, by giving his opinion on cases propos'd, and reasoning with his tutor on fit instances, than by giving a silent, negligent, sleepy audience to his tutor's lectures; and much more than by captious logical disputes, or set declamations of his own, upon any question. The one sets the thoughts upon wit and false colours, and not upon truth; the other teaches fallacy, wrangling, and opiniatry; and they are both of them things that spoil the judgment, and put a man out of the way of right and fair reasoning; and therefore carefully to be avoided by one who would improve himself, and be acceptable to others.
John Locke
Hume, David
Humphrey, Hubert
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