[astrofan]

I read in Organic Chemistry by Wade (8ed) that Hammond's Postulate suggests that "molecules having similar energies are also similar in structure". I was totally fine with it until I read the wikipedia page (https://en.wikipedia.org/wiki/Hammond%27s_postulate) which said

"Hence, if the tertiary transition state is close in structure to the (low energy) reactants, then it will also be lower in energy because structure determines energy."

I can not really make sense out of it since it sounds like a reverse statement.

To my understanding, it is the similarities in energy that determines the similarities in structure. The wording on the wikipedia page however suggests the reverse logic (as stated above).
[In terms of logic, p → q does not equate to q → p !]
Can anyone help clarify matters?

Additionally, I also have a problem when trying to apply Hammond's Postulate to kinematic and thermodynamic products. It seems to me that the direct implication of the postulate (if my problem above is solved) is that there could only be the thermodynamic product since a lower energy end state would equate to a lower energy transition state! Any ideas?

[phth]

I think that its saying the same thing, but it's written poorly.  The lower energy reactant does not equal a lower transition state, and if it did, then the laws of thermodynamics would be false.   The wikipedia page is saying that since the kinetic product has a lower activation energy, then the transition state will look more like the kinetic product.  The thermo product is farther away, so its ts^≠ will be not as similar as the kinetic product because it has a lower activation barrier by definition. 

[NewmanProj]

In any reaction pathway involving a single transition state, the transition state structure will resemble that entity, reactant or product, that is closest in energy to the transition state.

       TS

A

              B

Draw the energy curve for the reaction A -> B. Does the transition state most resemble A or B?