There shall be a provision that the policy, together with the application therefor, a copy of which application shall be endorsed upon or attached to the policy and made a part thereof, shall constitute the entire contract between the parties and shall be incontestable after it shall have been in force during the lifetime of the insured for 2 years from its date, except for non-payment of premiums and except for violations of the policy relating to naval and military services in time of war, and at the option of the company provisions relative to benefits in the event of total and permanent disability and provisions which grant additional insurance specifically against death by accident may also be excepted.