Graeme Hanigan of “The Celestial Teapot” reviews Homeopathy.  Graeme writes:
The following explanation for homoeopathy is taken from the Australian Homeopathic Association.

Homeopathy is a complete system of medicine developed by German physician and chemist, Dr Samuel Hahnemann (1755-1843), based on the principle of “let likes cure likes”. This law or principle is based on a long held belief as far back as Hippocrates, the Father of Medicine, and other ancient healers such as Paracelsus, that substances that produce symptoms in a healthy individual can be used to treat similar symptoms in a sick person.

Let’s take a critical look at this statement.

Homeopathy is a complete system of medicine

This is an extraordinary claim requiring extraordinary evidence to support it.

… developed by German physician and chemist, Dr Samuel Hahnemann (1755-1843).

This statement is supported by historical data and can be considered to be true. It also accurately acknowledges that homeopathy was developed rather than discovered by scientific deduction.

….based on the principle of “let likes cure likes”

This statement lacks scientific evidence to support it. The homoeopathic process of ‘proving’ claims to use the law or principle of “like cures like” although this law has never been demonstrated scientifically and relies heavily on confirmation bias for validation. Confirmation bias is the most common single flaw in human thinking and occurs when we favor information that confirms and reject information that contradicts our preconceived ideas.
1.  Here we confront the first logical fallacy of using an unknown (“let likes cure likes”) to explain an unknown (homeopathy). The statement fails Ockham’s razor, the very first filter of critical thinking.
In the following statement we confront the second, third and fourth logical fallacies.

This law or principle is based on a long held belief as far back as Hippocrates, the Father of Medicine, and other ancient healers such as Paracelsus, that substances that produce symptoms in a healthy individual can be used to treat similar symptoms in a sick person.

2.  The second logical fallacy is called a non-sequitur, just because a belief is long held, does not make it valid.
3.  The third logical fallacy is argument from authority. The implication being made that Hippocrates, the Father of Medicine and other ancient healers such as Paracelsus are reputable authorities on homeopathy, which they are not.
4.  The fourth logical fallacy is a tautology by claiming that “that substances that produce symptoms in a healthy individual can be used to treat similar symptoms in a sick person” without providing any supporting evidence.
So let us look further afield to the British Homeopathic Association for a plausible explanation of how homeopathy works.

The dilutions and the memory of water theory
One of the leading current proposals for how such ‘ultramolecular’ dilutions work is that water is capable of storing information relating to substances with which it has previously been in contact.

The memory of water theory has been around since 1988 so it’s hardly current.
5.  Here we encounter a fifth logical fallacy by way of another tautology in the claim “how such ultramolecular’ dilutions work” without providing any supporting evidence that they do work.
6.  Here we encounter the sixth logical fallacy called the slippery slope. “that water is capable of storing information relating to substances with which it has previously been in contact.”
The slippery slope works like this:
If water has a memory of substances it has been in contact with it is reasonable to suggest that it has a memory of all substances it has been in contact with over the 3.5 billion years that it has existed. Surely it would already have a memory of every substance in existence including a memory of the substances that it is exposed to during homeopathic potentising.
Potentising would not add any memory to water that it didn’t already have.
The extraordinary claims made for homeopathy are unsupported and implausible. When subjected to scientifically based clinical trials, it has been shown that homeopathy has no better efficacy than a placebo.
Which raises a number of Questions;
1.  We expect evidence based medicine from pharmacies, so why do they sell homeopathy?
2.  If Homeopathy is unable to delivery any efficacy beyond the placebo effect, why isn’t it considered to be a fraud?

Ed: Many thanks for writing your “Critical Look”  Graeme.
If you’re skeptical and live in and around the Mornington Peninsula, you might be interested in taking part in The Celestial Teapot meetup group.
The web site of the Celestial Teapot can be found here.