Biology
Biology is the natural science that involves the study of life and living organisms, including their physical structure, chemical composition, function, development and evolution. Modern biology is a vast field, composed of many branches. Despite the broad scope and the complexity of the science, there are certain unifying concepts that consolidate it into a single, coherent field. Biology recognizes the cell as the basic unit of life, genes as the basic unit of heredity, and evolution as the engine that propels the creation of new species. Living organisms are open systems that survive by transforming energy and decreasing their local entropy to maintain a stable and vital condition defined as homeostasis. See glossary of biology.
Cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread to other parts of the body. Possible signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss and a change in bowel movements. While these symptoms may indicate cancer, they may have other causes. Over 100 types of cancers affect humans.
Therapy
Therapy (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a diagnosis. In the medical field, it is usually synonymous with treatment (also abbreviated tx or Tx). Among psychologists and other mental health professionals, including psychiatrists, psychiatric nurse practitioners, counselors, and clinical social workers, the term may refer specifically to psychotherapy (sometimes dubbed 'talking therapy'). The English word therapy comes via Latin therapīa from Greek: θεραπεία and literally means "curing" or "healing".
Cancer
We "need" cancer because, by the very fact of its incurability, it makes all other diseases, however virulent, not cancer.
Gilbert Adair, journalist and film critic, "Under the Sign of Cancer," Myths and Memories, 1986.
Biology
I like to define biology as the history of the earth and all its life — past, present, and future. To understand biology is to understand that all life is linked to the earth from which it came; it is to understand that the stream of life, flowing out of the dim past into the uncertain future, is in reality a unified force, though composed of an infinite number and variety of separate lives.
Rachel Carson Preface to Humane Biology Projects (1961) by the Animal Welfare Institute
Therapy
Therapy is not to "talk about" things, but to change the person's life, and to relieve suffering, such as depression, anxiety, or relationship problems. Of course, empathy and skillful listening are important at the start of each session, but they are simply not sufficient to change the patient's life.
David D. Burns, in: Ryan Howes "Seven Questions for David D. Burns" at psychologytoday.com, 7 January 2009.