9/12/03- Philosophy of Science and Biology Rennaissance - rebirth of art - rebirth of science - Physics - Biology rudimentary, a lot of Physiology (DaVinci) - renewed activity of Philosophers of Science Philosophy of Science- focus on Physics - Physicalism- all sciences can be reduced to the laws of Physics. - 3 kinds of physicalist reductionism- - constitutive- all sciences' subjects are made up of molecules and atoms, and these of course are understood in physics. This is the only form of reductionism that has had any success. - explanatory - science is based on a hierarchy of knowledge, annd all levers can be understood in terms of the hierarchical level below. I.e., there are no emergent properties. - theoretical - all laws in other sciences are special cases of the laws of physics. NOTE- the distinction between these last two kinds of reductionis is dicey. You will need to know about the first one. - Vitalism- an alternative to Physicalism that has emerged more recently. - True Vitalism - a belief in the spiritual as the reason that some things cannot be explained by Physics, or even science - examples- the Holy Ghost, Karma, The Force, a soul - Organicism - viewpoint that biology is distinct from the other sciences, has emergent properties. Reasons Biology is distinct from Physics - complexity- biological systems are layers and layers above molecules and atom, layers built upon each other - populations- biological organisms are organized into populations, which must be considered dinstinctly from individuals. - coded information- organisms have coded information that describes how to make an individual. Even more importantly, this information is passed on to the offspring for generations, eons, since the beginning of life. - nature and acquisition of knowledge (see below) The Nature and Acquisition of Knowledge, what knowledge means and how we learn as a society, has changed in recent years, at least partly because of the growth of Biology and respect for it. In the two lists below, the first item applies to classical or traditional Physics, and the other methods apply to Biology as well as other fields of science includng Physics. - Nature of Knowledge - Law- absolute truth, can be proven in mathematical terms, provides predictions that never fail. - Theory- hypothesis that has never been disproven, generally accepted as true, but may be impossible to formally prove, sometimes has exceptions - Hypothesis- an idea based on information/observation, may be disproven or supported by further experimennt or observation - Observation- not respected as a form of knowledge in itself in traditional physics but rather taken as data suporting or disproving hypotheses or theories. Biology is so rich and poorly understood, a lot of basic observation still has to be done and is very important - Acquisition of Knowledge - Experimental Methods- this is strictly following the 'Scientific Process' that we talked about in the study: material and methods includes precise information to do an experiment with controls, which will give an answer that supports or definitively refutes a hypothesis. A controlled experiment may have a bunch of variables, but only one variable is manipulated at a time. The experiment is done twice in parallel, in two treatments: an experimental treatment in which the variable is manipulated, and a control treatment in which the variable is not. This way an effect (difference between the two treatments) can be assigned to the experimental variable. - Comparative method- often in biology some systems cannot be manipulated in experiments. Observations from such systems are compared to systems in which experiments have been done assuming that the results would be the same. For example, we cannot breed humans, but we can breed mice. Genetic experiments in mice have found genes involved in obesity and hypertension, and we believe the same genes are important in those disorders in humans. Often these conclusions are based on observations in the humans such as specific chemical imbalances in nerve cells that are similar to those observed in mice where the defect is known to be caused by the particular gene. - Observation- Just emphasizing that observation is a powerful form of knowledge and way of acquiring knowledge, particularl at this time in biology because there is so much we do not know. Evolution in Biology- in 1859, Charles Darwin published On the Origin of Species. (he delayed publication because he wanted just the right public perception and response from his peers.) (It is worth pointing out that other biologists were thinking about evolution, so it is not right ot say that Darwin discovered evolution. He is credited with discovering evolution, in particular evolution by natural selection.) Anyway, his book sold out in the first day. It sold out several volumes in the first year. It was immediately accepted and believed by the educated upper class in England (where it was published). Scientists immediately accepted evolution as the underlying, unifying theme in biology, and its role as such as grown and developed since then. Evolution was seen as a historical process, with a 'memory', but NOT with any purpose or foresight. In the U.S., Origin of Species had a similar reception among educated people in cities in the north, but in the south, there was a religious fundamentalism that people saw as inconsistent with evolution. This fundamentalism was caused by tough times brought on by loss in the Civil War and poor peoples' struggle for subsistence. All of this discussion of evolution, complexity and emergent properties and so on assumes NO higher purpose or directionality. To say that we are more advanced than bacteria is meaningless. That nature exists for some higher purpose is called teleology. Teleology is generally rejected in the philosophy of science. As noted above, constitutive reductionism is the only form of reductionism and phyicalism that has had any success, but it tells us how things happen, not why things happen. Evolution tells us why things happen. Two forms of explanation- - proximate- How- constitutive reductionism - ultimate- Why- evolutionary biology.