clear thinking

References in classic literature ?
The events of the previous evening had made me nervous and ill; I had tried to cure myself and attain to clear thinking by walking in the open air, but I was oppressed with a horrible presentiment of evil--a presentiment which I could not formulate.
Moral considerations greatly increase the difficulty of clear thinking in this matter.
The lack of joined-up, clear thinking starts with the Secretary of State for Transport's decision to abandon electrifying the rail line beyond Cardiff; so that the use of diesel locomotives will continue until replaced by hybrid diesel and electrical ones.
Both of these are good because they require not only fine movements of the arms, hands and fingers, but clear thinking.
The Horse That Won't Go Away: Clever Hans, Facilitated Communication, and the Need for Clear Thinking
Peter's call for clear thinking about objectives is very pertinent if we are thinking what is we are striving for.
There is no way to write a six-page, narratively structured memo and not have clear thinking.
The scarcity of clear thinking extends to Westminster, where the Government plans to place graphic illustrations of the consequences of smoking on cigarette packets.
There is no evidence that knowledge of Latin is injurious to our understanding of English and clear thinking.
Germany legend Jurgen Klinsmann, meanwhile, has warned Greg Dyke and the members of the FA commission detailed to sort out the English game that it will take a lot of clear thinking to introduce so many changes.
However, an expert has claimed that life doesn't work this way and that irrespective of achieving our image of happiness, success or the desirable life, pain still persists and although positive thinking is helpful, it's not so much as positive thinking as clear thinking, the Sydney Morning Herald reported.
Winston Churchill once said that "the endless repetition of history" is defined by "unwillingness to act when action would be simple and effective, lack of clear thinking," and "confusion of counsel until the emergency comes, until self-preservation strikes its jarring gong.