"HUMANISM IS ONE OF THE FEW PHILOSOPHIES OF LIFE THAT ENCOURAGES.... IN FACT, DEMANDS CRITICAL THINKING AND THE SCIENTIFIC METHOD IN THE HUMAN QUEST FOR TRUTH."

Reliable Knowledge

'Reliable' means that when we apply it, e.g. to deduce something else, such as a prediction of some future occurrences - then it doesn't let us down.

For example, I've observed that the sun rises every morning (at least, those mornings on which I've been up early enough, and looked). On the basis of that knowledge, I have predicted that the sun will continue to rise every morning. The next time I checked, it did indeed rise, and now I have more confidence that my knowledge that 'the sun rises every morning' is reliable.

I'm not saying that it's 'correct', or 'true'; only that it works well enough for me, for the time being. I'll trust it until such a time as I see a need to modify it (e.g. astronomers report a massive black hole racing towards the solar system...).

Fallibility and Skepticism

How can we obtain reliable knowledge?

Appeal to Authority

As children, we learn to ask our parents or teachers. "Mom/Dad, why doesn't the Moon fall down?" "Son, it's because it's too high for the Earth's gravity to reach". Well, we soon learn too that although some people might be right annoyingly often, nobody is infallible.

How about looking up the answer in books? Presumably, facts that are stated in print, especially in reputable publications, by reputable authors, are likely to be 'reliable'. This is a good method most of the time, but most people know that "you can't believe everything you read", and there have been plenty of instances of supposedly trustworthy publications getting things plain wrong.

Authority is not always a reliable source of knowledge, whether its people, books, or anything else. For practical purposes we usually accept what they say as probably correct because we can't check everything. However, trying to answer questions of nature correctly requires extreme care - history has shown repeatedly that people can draw the wrong conclusions from the evidence of their senses.

Misinterpretation of data

Drop a lead ball and a feather at the same time (in air) and the lead ball reaches the ground before the feather. Therefore heavy objects fall faster than light objects? No! In a vacuum the feather, unimpeded by air, reaches the ground together with the lead ball.

Another example is that the sun can be seen to rise in the east, and travel in an arc over to set in the west. Therefore the sun goes around the Earth? No! But this is what people truly believed for most of mankind's history.

Even given reliable data, we may easily draw the wrong conclusions, perhaps because we don't understand the principles of logic, or the limitations of statistics. Suppose that a survey shows that 20% of all road accidents are caused by drunk drivers. So 80% of all road accidents are caused by sober drivers. Therefore, it's safer to drive drunk... Why is this a false argument? There are many more like this that appear in the media, and everyday life. Particularly prevalent is the fitting of theories to random data - because there'll always be patterns you can see after the fact. Shuffle a deck of cards, then drop them face up on the floor. Oh, look! There are three kings together - it must mean something! Even in a truly random sequence, 'unlikely things' must happen sometimes.

Not only do we too easily draw the wrong conclusions from the given evidence, but we can all too easily 'see' things different than how they really are, or are not even there at all! For example, optical illusions

In fact, a theory is never held to be 'true' in any absolute sense; science does not prove anything (only mathematics does that, of mathematical statements) - it only offers tentative working models of the physical world, as agreed upon by several independent researchers after they have impersonally tested the evidence for themselves, and considered if there might be better explanations.

Nor is any theory ever immune from challenge; they may serve for a long time as foundation for much else in science, but if they fail to account perfectly for everything you'd expect, then they may be superceded by a 'better' theory - as happened with Newton's laws of gravitation and motion. Those laws aren't wrong - at everyday scales, but for near-light velocities, or strong gravitation fields, Einstein's theories work better.

In science, all claims are tentative, subject to revision on the basis of new evidence. Although science cannot provide one with hundred percent certainty, yet it is the most, if not the only, objective mode of pursuing knowledge. Science is above all else a critical and analytical activity and the scientist is pre-eminently a person who requires irrefutible evidence before he or she delivers an opinion.

Occasionally, experimental data just cannot be explained with any reasonable extension of existing theories, and someone will try a radical new approach (or 'paradigm' as Thomas Kuhn calls it). This new approach may be so strange and against prevailing 'common sense', that other (perhaps older) scientists are unable to accept it, but eventually the weight of the evidence and the predicitng power of the new theory win out, and the old theory is abandoned. The change in world view can be so radical as to constitute a 'revolution', rather than the more gradual evolution of 'normal science'.

·         Objective Experimentation and Observation.

Science depends heavily on the repeatability of experiments, and on their giving consistent (e.g. almost identical) results. This repeatability hinges on objective comparison of observations of different researchers studying the phenomenon.

Objectivity indicates the desire to observe things as they are, without manipulating the observational results to accord with some preconceived world view. All observation is potentially contaminated, whether by our theories or our worldview or our past experiences.

Scientists, like anyone else, may be swayed by some preconceptions to look for certain experimental results rather than others. Scientists are people and suffer the flaws of humanity too, and it cannot truthfully be said that every scientific theory has arisen from a perfectly executed process of 'scientific method'.

Scientists have desires, opinions, and biases that may sometimes influence them in the selection of their data and hypotheses - even, very ocasionally, to the point of fraudulence. We trust that this is very rare, and that science is a self-correcting process with checks and balances - such as empirical replication, and peer reviews of published work. The scientific community as a whole, however, judges the work of its members by the objectivity and rigor with which that work has been conducted.

An infamous example of an experiment that couldn't be repeated to give the same results again, involved "cold fusion" - a supposed process by which nuclear fusion could be achieved at room temperatures instead of the extremely high temperatures normally needed for fusion to occur. The researchers involved in the original experiment were found to have been less than objective in their methods.