One of the key underlying assumptions of science is that human sense perception is able to accurately detect the nature of reality. Where devices are used to confirm or enhance human perception (eg camera, thermometer, computer, geiger counter... and many others) then human sense perception is still required to confirm those device's results.
This underlying assumption itself cannot be tested by science because it must first be assumed before science can begin.
This leads to a couple of necessary conclusions which are very significant:
- Science is entirely based on faith. (ie faith in the underlying assumptions of science)
- To the extent that Atheism relies on science (as the only reliable source of truth) it is thus also entirely faith based.
However science produces useable results. It is able to back itself up with lots and lots and lots of tests for validity, there are limitations and science makes a certain number of assumptions, generally science will accept the explanations that make the fewest assumptions, this is a principle called Occam's Razor. And of course, they're accepted if there's enough evidence to support it. In regards to how we measure science and human perception. Yes, we do rely on the idea that the data we receive is accurate and we assume the reality we experience through our senses are accurate. Of course, we could all live in the Matrix and our would could be a lie, it could be like Plato's allegory of the cave. The problem with unknowns is that they're unknown, this is why we use the scientific method, we can measure the data we have, we can build and build on that data and learn more and more about the environment. I would not say individual perception gets in the way, as for anything to become a theory, it is tested and tested and tested and not all by one person. Scientists try to avoid individual bias by having such a rigorous process.
Whilst I understand science does not have a perfect assessment of the way things work, but there is a high degree of accuracy, we can tell things because of the results it has produced. Without our scientific understanding things like modern medicine, space travel, GPS, computers and various things we rely on in our day-to-day lives. To my mind, science isn't entirely based on faith, whilst I'll admit there is a certain amount of faith, as I know the scientific process, I myself have not analysed the data nor do I have a PHD in any of the sciences - so I am relying on the scientific community to stick to the scientific process. Would you say the procedure for successfully completing brain surgery is completely based on faith? No, the procedure is a result of years of medical science. To say science is faith based is an over simplification and one that's seemingly based on ideas related to Plato's allegory of the cave, the idea that the reality we see is not necessarily the reality that's out there and pretty much creates the argument, "everything is faith".
For that reason, you may wish to call empiricism 'faith-based' on any imaginary scenarios where our senses are unreliable, but this is seemingly an attempt to try and devalue the scientific approach to put it on the same level as anything that's 'faith' based, like religion. Science has so much more to offer to back itself.
Also, two things about atheism. One, it's not capitalised, it's 'atheism' not 'Atheism', just as 'theism' is not 'Theism'. One is an abstract noun, whilst the other is a proper noun, 'atheism' is a lack of belief in any deities, 'Atheism' implies the name of an organisation or group of people united by common ideals, like 'Christianity' or 'Marxism'. The reason I feel the need to point that out leads into point 2. People tend to think of atheism as a group or organisation of people united by common ideals, which includes disbelief in deities, science, Evolution, criticism of religion and humanism. Atheism is no way relies on science, this is a misconception. Many atheists may rely on science, but this is not the same thing, many Christians do too...even the ones not willing to admit it. 'Atheism' is not the name of something, it merely describes a quality in a person.
Atheism is the lack of belief in any deities, nothing else. Hence many Buddhists are considered atheists, as Buddhism is a religion without a deity, theistic Buddhist either deify Buddha or belief in the god(s) of another religion. Siddartha Gautama was a Hindu, hence the Hindu gods are sometimes acquired, but it is by no means a part of the Buddhist religion.