Science is an ongoing attempt to explain the universe and in this respect, is attempting to explain all that is observable. Science is not absolute and the rational minded would not claim so or that it has the absolute answer to anything. So, what is truth? Truth is something which is absolutely correct, without doubt, and the polar opposite of something which is not true. Truth is a binary concept, something either is true or it isn't and anything that is not true must include those things which are not entirely true. Consider the simple statement, "The bath is full". This would be generally regarded as true if the bath was, "full of water" but, logically the statement can only be true if the water in the bath were lapping at the very top, that no more water could enter that bath without a change of conditions affecting the observation. Conversely, the statement cannot be true if there were no water in the bath at all or if there were any amount of water in the bath between empty and full. In other words, evaporation notwithstanding, if any amount of water can be added to that bath without spilling water over the side then the bath cannot have been full even though it may appear to be so. The essence of science is that it derives its confidence from accumulated observations and a rational interpretation of the same. Science has little to do with truth or certainty because nothing in science is above challenge and, even though it may seem to be at times, cannot be considered absolute. Something can be considered to be correct for decades and can be confirmed by hundreds or even thousands of observations but it only takes one verified challenge to bring that theory to its knees and force its removal or change. Yes, science, or rather scientists, can be extremely stubborn at times but the philosophy was created by scientists, is administered by scientists and scientists are human. Humans can be hard to shift from a given point of view and, even if we can see examples of that now, in principle the above is correct. Let us consider the favourite target of the religious fundamentalist, the Theory of Evolution. Evolution is now considered so safe that nothing could shake it as a theory yet, in actuality, all it would take would be one piece of verified evidence that the hand of deity was involved and evolution as a theory would die. Granted, it would stumble on for a while not realising it had been beheaded but ultimately, were that observation confirmed, it could no longer be accepted. However, no such evidence has been uncovered, more and more confirmatory evidence continues to be discovered in support of it and, though it has changed in fine, the Theory of Evolution has remained unfazed by all comers since its birth a century and a half ago. Science is the recognised method of discovering things about the universe and it does it not by deductive reasoning but inductive. The inductive method, instead of building conclusions on a set of assumptions deductively, builds on a set of observations and derives generalisations from them and the modern scientist looks on induction as the essential process of gaining knowledge, the only way of justifying a generalisation. Moreover, the modern scientist recognises that no generalisation can be allowed to stand unless it is continually challenged by newer methods and techniques. The upshot is that no amount of inductive testing can make a generalisation absolute and from that arises the scientific necessity that all of science is tentative. As a result, modern natural philosophy makes no attempt to attain ultimate truth because there can never be sufficient observations to achieve such a status. This is also the reason why modern science cannot investigate claims such as god, spirit and soul as it is not possible to build a generalisation without observation and verifiable observations of such phenomena have yet to be gained. Furthermore, the more we progress, the more we know, the less likely they appear because non-testable phenomena lie outside of the sphere of inductive science. The piece-de-résistance of science is, of course, the peer-review process. Peer review does not, as some critics would have us believe, hobble the search for knowledge but in fact opens up the whole of modern natural philosophy to all of the scientists all of the time. The simple act of publishing one's work brings a given generalisation into an arena where it can be tested by others. Peer-review is a formalised version of scientific challenge and the difference that process makes is immense, everything every scientist does is potentially checked by others. That doesn't stop mistakes or fraud but it does mean that mistakes, purposeful or otherwise, will, with near certainty, be uncovered and reversed. Critics are fond of highlighting the mistakes of science, Piltdown man, Nebraska Man and more besides but such examples are more notable for the fact that it was science that uncovered the fraud or flaw. In that sense, such examples are better viewed as examples of science doing exactly what science should, self-correcting. It is also why such critics dare not publish their own "research" in reputable journals preferring to appeal to likeminded individuals and promoting the lowest forms of reasoning to the general public. They know that if they tried to publish in respected journals, their claims would be ripped to shreds so quickly it would hardly have been worth applying their twisted reasoning to paper. As initially stated, science is an ongoing and self-correcting attempt to understand the observable universe implicitly meaning there is more to discover and that everything is up for challenge. The nature of science, the very fact that it is capable of admitting to and correcting its errors and claims only tentative knowledge, means one cannot say definitively that any or all of science is correct. Simple logic, as evidenced by the huge number of scientific ideas that have been modified, overturned or dismissed, shows that no part of science can be considered so safe it is beyond challenge. Science deals with facts, theories and hypotheses, is wholly open to challenge and, in this light, science represents our best current attempt to understand the nature of the universe around us. Science doesn't claim to be inerrant. Science does not claim to possess an answer to every question. Science does claim to be absolute. Science's only real claim is to represent our best current understanding of the universe around us and rightly shows no respect for those that place their faith before cold hard fact and a reasonable interpretation of the same, which is why science cannot be absolute and why it has little to do with truth. And to the final question, how do we know that science works? As one engineer famously put it, "Because the bridges stay up."