Thank you Kurava for this short and very precise post.
I am taking the liberty to comment.
The main difference in compassion from an atheist and a Buddhist view points would be :
1. ONE LIFE ONLY
Atheists' compassion arise from seeing sufferings in the present life only.
The help offered by them is thus also limited and temporal.
An atheist is one who has achieve the conviction that the mind equates with the perishable, that is: when my body dies, my entire being disintegrates and disappears and ceases to exist in any form, there is no next rebirth, there is no karma.
Then indeed compassion is limited to that understanding.
When one cannot understand the suffering experienced after this body has ceases to live, then one may even see death as a better option in some cases, such as severe disease or severe depression.
Then out of compassion, an atheist could even envisage death as a solution.
When applied to others: euthanasia.
When applied to one self: suicide.
Clearly then, an atheist's belief, and even the result of his very compassion can be rather damaging to others and to one self.
2. KARMA
Buddhists understand that sufferings experienced in this life time are results of actions committed in the past or past lives.
Buddhist have learned the 2nd Noble Truth, they have debated it, they have understood it, they have applied its understanding to the reality they have experienced and they have validated the 2nd Noble Truth as real. They are now aware of what causes the 1st Noble Truth to be experienced. They are wiser, they have given up superstition.
1st and 2nd Noble truth = karmic wheel in motion to create more suffering.
Buddhists know the method of how to end sufferings permanently.
Buddhist have learned the 4th Noble Truth, they have debated it, they have authenticated it, they have applied its understanding to the reality they have experienced and they have validated the 4th Noble Truth as real because they can already experience its benefits. And with faith in the 3rd Noble Truth, they are now aware of what causes the 3rd Noble Truth to be achieved, they know what causes are for achieving the cessation of suffering. They are wiser, they have given up superstition.
3rd and 4th Noble truth = karmic wheel in motion to create causes for the cessation of suffering.
3. MY COMPASSION IS LIMITED TO MY UNDERSTANDING OF SUFFERING
Atheists' understanding of suffering is the gross form whereas Buddhists' understanding of suffering is broken into :
a) manifest pain (what most of us can relate to),
b) changing suffering,
c) pervasive suffering.
If I cannot conceptualize a suffering, it is impossible for me to have compassion upon that specific suffering.
When I see someone who just broke his leg, I do not suffer, my legs are fine, but I can conceptualize the suffering that the other person is going through by analogy and imagination. I can feel the suffering because I have conceptualized it first. Then, on the basis of this conceptualization and on the basis of love, I can feel this suffering, and I simply cannot bear it, that is compassion.
If I see someone's birthday party pictures on facebook, can I conceptualize suffering and develop compassion?
When I see someone is getting a job promotion, can I conceptualize suffering and develop compassion?
When I see someone lying or abusing others, can I conceptualize suffering and develop compassion?
When I see a new born baby, can I conceptualize suffering and develop compassion?
When I see a pregnant woman, can I conceptualize suffering and develop compassion?
As a Buddhist, we should be able to see the suffering in these situations, a direct pervasive suffering and a latent suffering of change.
4. BODHICITTA
With the correct understanding of true suffering, Buddhists pursue the spiritual path of enlightenment with the compassionate mind of elevating others from unending suffering to ultimate happiness.
no comment.