Faith & reason
To understand the difference between religion, ideology, philosophy and science, it is important to first distinguish between two fundamentally different approaches towards the interpretation and analysis of information : faith & reason.
Faith
Wikipedia uses the following definition :
Faith is confidence or trust in a person or thing; or the observance of an obligation from loyalty; or fidelity to a person,
promise, engagement; or a belief not based on proof; or it may refer
to a particular system of religious belief, such as in which faith is confidence based on some degree of warrant.
Faith is typically a subconscious process, that works through emotion. It is typically driven by processes at the instinctive or intuitive level that one is not consciously aware of.
Depending on who you talk to, being faithful is either considered a good thing or a bad thing :
I believe in Christianity as I believe that the sun has risen: not
only because I see it, but because by it I see everything else.
― C.S. Lewis
Faith: not wanting to know what is true.
— Friedrich Nietzsche
When we blindly adopt a religion, a political system, a literary
dogma, we become automatons. We cease to grow.
— Anais Nin
Reason
Wikipedia uses the following definition :
Reason is the capacity for consciously making sense of things,
applying logic, establishing and verifying facts, and changing or
justifying practices, institutions, and beliefs based on new or
existing information. [...] The concept of reason is sometimes
referred to as rationality.
Reason is a conscious process, that may or may not take emotions into account (albeit at a conscious level).
Some would argue that reason is higher than faith and that a great capacity for reason eliminates the need for faith :
The way to see by Faith is to shut the Eye of Reason.
— Benjamin Franklin
We may define ‘faith’ as the firm belief in something for which there
is no evidence. Where there is evidence, no one speaks of "faith." We
do not speak of faith that two and two are four or that the earth is
round. We only speak of faith when we wish to substitute emotion for
evidence.
— Bertrand Russell
All our knowledge begins with the senses, proceeds then to the
understanding, and ends with reason. There is nothing higher than
reason.
— Immanuel Kant
Others would argue that faith and reason are complementary. They would argue that faith can (and should) be used wherever reason does not provide us with answers :
Faith consists in believing when it is beyond the power of reason to
believe.
— Voltaire
Reason is our Soules left hand, Faith is her right, …
— John Donne
Faith certainly tells us what the senses do not, but not the contrary
of what they see; it is above, not against them.
— Blaise Pascal
Religion, ideology, philosophy, science & pseudoscience
Religion, ideology, philosophy and science are different but related approaches to understanding the universe around us. Herebelow, I try to explain the difference, as well as the difference between what qualifies as science and what qualifies as pseudoscience.
Religion
Religions are humanity's first approach to understanding the universe. They typically start with a charismatic guru-type figure, like Zoroaster, Moses, Gautama Buddha, Jesus Christ, Muhammad, Joseph Smith and Bahá'u'lláh. Typically, these individuals were known for their great wisdom and were responsible for a major social overhaul that improved the lives of thousands (if not millions) of people in just one generation.
By becoming known as "saviors" during an era of great despair, subsequent generations started relying on words of their "savior", which was usually first past orally and later past in written form. Because it helped them survive and/or achieve social status, the words of the "savior" defined how people lived their lives.
Some religions allow for constant interpretation and re-interpretation of the words of the "savior". A typicaly example would be Judaism, where generations upon generations of rabbis have added their own interpretations of Judaic law to refine it or modify is for more "modern" times. As such, the original 10 commandments of Moses evolved into the 613 mitzvot, first mentioned in a sermon by 3rd century Rabbi Simlai, recorded in Talmud Makkot 23b. And even then, Judaic lore kept evolving with each generation of rabbis, with the most traditional form of European Judaism drawing heavily on the 16th century Lurianic Kabbalah.
Other religions allow little interpretation. One of the more extreme examples are Biblical literalists, who consider every word of the Bible as the literal word of the Christian God. Biblical literalism is mostly popular among Evangelical Christians, which is rather unpopular in Europe but very strong in the US. According to a 2011 Gallup survey reports, about 33% of the American population belongs in this category.
By heavily relying on the "revelations" of one or more charismatic figure, religions are meta-frameworks strongly rooted in faith. However, they can and often do involve reason to refine and update those revelations for later generations.
The "savior" upon which a religion is grounded can be deified by followers of that religion, but this isn't the care per se. Not all religions involve a "savior" figure that "supernatural" powers are attributed to.
Ideology
Like religions, ideologies typically start with a charismatic guru-type figure : think of Karl Marx, Adolf Hitler, Mao Zedong or Kim Il-sung. Like religions, ideologies draw heavily on the words of those charismatic leaders. And like religions, ideologies are strongly rooted in faith.
So what's the difference between religions and ideologies? Some might argue that the only real difference between both, is that ideologies are secular. Ideologies do not presume the existence of magic or divine authority. Ideologies do not usually presume any correlation with supernatural.
However, this distinction is rather arbitrary and there are many shades of grey. For example, Hitler believed to be divinely inspired and the way Kim Il-sung is venerated and mythologised in North-Korea today can hardly be distinguished from the way Jesus or Muḥammad are venerated in their respective religion. So ideology could be just be the initial phase that every religion passes before it becomes a religion.
Philosophy
Philosophy is different from religion in the sense that it is not so much rooted in faith as it is in reason. While philosophy neither excludes nor requires faith, philosophy is an approach to understanding that focuses on reason.
While philosophy still approaches many charismatic figures from the past as authorative figures, those figures aren't given the same dogmatic treatment given to the charismatic founders of religious movements. Men like Aristotle, Kant or Stirner are treated more as sources of inspiration rather than authorities that are not to be questioned. This, in turn, makes philosophy more open to dissenting views and data that contradicts dearly held views.
Consistent logic is the very foundation of all philosophy.
Science
Science takes the approach of philosophy a step further by rejecting all faith as a valid approach to the establishment of truth. Where philosophy only requires consistent logic, science adds to these requirements the need for empirical evidence and interpretation in accordance with the scientific method.
A claim is not scientific if it is not (1) supported by a consistent and logical interpretation in accordance with the scientific method, (2) either explicitly suggested or at least supported by empirical evidence as well as (3) consistent with the body of evidence established in accorandance with the first two principes.
If a scientist makes a claim that happens to be consistent with the first two principes but not with the third, he must first point out errors in the the body of evidence established in accorandance with the first two principes and correct those errors in a manner so his new claim is no longer incompatible with the third principle. By these means, science is self-correcting, which allows for the scientific body of evidence to be gradually improved.
Pseudoscience
It is important to distinguish science from pseudoscience, which involves any claim, belief, or practice presented as scientific, but which does not adhere to the scientific method. A field, practice, or body of knowledge can reasonably be called pseudoscientific when it is presented as consistent with the norms of scientific research, but it demonstrably fails to meet these norms.
To put it differently : pseudoscience is the disguise of ideology, religion or plain nonsense as science. Pseudoscience can be fringe, but it doesn't need to per se. Pseudoscience can be totally mainstream and it's possible for a claim to be both pseudoscientific and for it to be supported by the majority of the population.
For a claim to be pseudoscientific, it neither needs to be unpopular nor false. All it takes for a claim to be pseudoscientific, is for it not to adhere to the three principles (see above) that scientific claims need to adhere to. As a consequence, pseudoscience isn't always obvious to distinguish from real science, even by scientists.
Peer review is a popular mechanism scientists used to distinguish actual science from pseudoscience, but it is a flawed mechanism, because a lot of modern science involves a highly detailed and highly technical expertise only a few people in the world possess. As a consequence, many scientists actually lack the knowledgeto qualify as the peers of the (pseudo)scientists whoes work they're expected to judge. Also, the purposeful falsification of data often isn't obvious to detect without repeating the exact same experiments. For both reasons, some pseudoscience manages to succesfully pass for actual science even among scientists.
With pseudoscience passing for science, it should not surprise anyone that the lines between religion and science aren't obvious to everyone. However, it should be noted that any any actual science ( = purged from pseudoscientific claims) is totally distinct from religion due to its total lack of reliance on faith whatsoever.
Afterthought
Let's go back to your question :
- How would it be possible for such a person to distinguish scientific facts from religious dogma?
- How can we convince such a person of the validity of ideas like those of modern cosmology or evolutionary biology, without first
having to teach them enough biology and physics to understand those
concepts?
I'm not sure you can, because - whether driven by religion or ideology - most people are not even capable of developing a worldview not guided by whatever faith they've developed during their upbringing :
Few people are capable of expressing with equanimity opinions which
differ from the prejudices of their social environment. Most people
are not even capable of forming such opinions.
— Albert Einstein
Note, however, that the Dalai Lama doesn't seem to qualify as "most people" :
If science discovers new facts that are not unifiable with Buddhism,
Buddhism will need to be changed appropriately
— Tenzin Gyatso, 14th Dalai Lama