EEC

 Cummings is doing a very Cummings thing here: breaking grammar to make the thought feel bigger than grammar.

A clean reading of it is:

Life is not something neat, orderly, or neatly contained like a paragraph. Death is not just a small interruption, an aside, or a brief pause like a parenthesis.

What’s going on in the lines:

“laugh, leaning back in my arms”

This gives a feeling of intimacy, ease, surrender, joy, being fully alive in the body and in love. It’s not abstract philosophy floating in space; it’s physical and human.

“for life’s not a paragraph”

A paragraph has structure, boundaries, a beginning and end, and tidy logic. Cummings is saying life does not work like that. It spills, surprises, resists clean explanation.

“And death i think is no parenthesis”

A parenthesis is a side remark, something secondary, tucked inside the main sentence. He’s saying death is not a minor interruption to life, not just a detachable aside. It matters. It is real, not decorative punctuation.

The deeper idea is kind of beautiful:

he rejects the idea that existence can be reduced to proper writing rules or neat literary form. Life and death are too wild, too profound, too unruly for that.

There is also a quiet contrast:

• paragraph = something organized and complete
• parenthesis = something secondary and enclosed

So he may be saying both:

• life cannot be neatly organized
• death cannot be made small or incidental

And because it’s Cummings, the broken spacing and odd capitalization help enact that meaning. He refuses tidy form while talking about how life is not tidy form. Sneaky.

One extra note: these lines come from a love poem, so the speaker is also saying this while holding someone. That makes it feel less like a cold statement about mortality and more like: because life and death are serious and immense, this moment of love matters intensely.

I can also give you a line-by-line plain English paraphrase of the whole poem.