Homeopathy: treats the disease, not just the symptoms like conventional medicine.

Short answer:

• No it doesn't, it doesn't treat anything
• The whole endeavour of homeopathy is based around only looking at symptoms, and not in determining the real cause of the disease.
• this is based on a complete misunderstanding of the way genuine medicine actually works

A little more:

This is a most interesting claim and it's based on three main incorrect assumptions:

1. That homeopathy works at all.
2. That homeopathy is concerned with anything other than symptoms
3. That conventional medicine only treats symptoms.

Claim 1 will be dealt with in a later post so we won't talk about it here, except to remind readers that there is no good quality, repeatable evidence from properly conducted trials to show that homeopathy is effective for anything, so we'll focus on 2 and 3.
Homeopathy was invented in a time when it was not understood that many diseases are caused by microbes, and therefore it has absolutely nothing to say about this. It's entire foundation is based on the "like cures like" principle that essentially says "substances cause symptom X can cure all diseases that also have symptoms like X." For example one of the indications of Arsen Album (That's arsenic to you and me) is purported to be for mouth ulcers, because if drink arsenic your mouth understandably becomes rather ulcerated. There are a number of causes (bacterial, viral, fungal etc.) of mouth ulcers, and homeopathy is silent on all of these, because it claims that all that is needed to select the correct treatment is a description of the symptoms, and the cause is irrelevant (Or perhaps some mythical "miasm"). Some go on to claim that what is happening is that the remedy is somehow activating the bodies own defences against the cause, but I have dealt with that already in another post.
When it comes to conventional medicine (often referred to as "Allopathy" by quacks and their adherents) the example is often given that a decongestant merely masks the symptoms of a cold, and therefore all of genuine medicine deals only with symptoms and not looking for the cause of the symptoms. This example is a ridiculous strawman argument, and the whole idea is just plain wrong. Antibiotics treat the microbes that are the root causes of disease, as do antivirals and antiretrovirals; vaccines prevent the root causes of disease; radiotherapy and chemotherapy eliminate the cancers that are the cause of distress; other treatments correct chemical imbalances that cause a variety of disorders. The accusation that genuine medicine does not consider causes is quite simply false. Of course there are medicines that seek to alleviate symptoms while the disease is otherwise treated, or while it resolves itself, or where there is no known cure, but it is an outright lie to suggest that all medicines are such.
The charge that conventional medicine sees patients as simply a collection of symptoms while homeopathy sees the whole patient and their condition is one that is designed to appeal to the emotion of the sufferer and make them feel cared for; it is not only wrong but is also more accurately levelled at homeopaths themselves. Homeopaths make this claim but cannot in any way substantiate it, while their whole methodology is based around the study of symptoms without any concern for the actual cause.