The philosophy has been in existence since the beginning of the school in 1968. Maclay School supports its students in fulfilling their potential academically, emotionally, physically, and artistically. Its purpose is:

• to establish and maintain a curriculum designed to teach the liberal arts creatively.
• to create a civilized community of learning guided by a dedicated faculty of superior qualifications.
• to provide patient and understanding ways to challenge each student.
• to engender, by teaching and example, self-discipline, hard work, integrity, and persistence at school and home.
• to stimulate each student to inquire, learn, recognize obligations, develop self-respect, and understand others.
• to build a meaningful spirit among students, parents, faculty, and community by faithful fulfillment of the Maclay School Mission and Philosophy.
• to prepare well-balanced students able to meet the future challenges of higher education, service to others, and life, with wisdom and fortitude.

As a member of the Maclay School community, I will maintain my honor and integrity at all times by creating and upholding an atmosphere of trust, respect, kindness, and consideration for all members of the school and the wider community. All constituencies that make up our community - trustees, administrators, faculty, staff, students, parents, and alumni - should respect, support, defend, cooperate with, speak well of each other and Maclay School, and place the best interests of the institution first.

At Maclay School, a sense of belonging is central to our mission as an educational institution. Diversity, equity, and inclusion are fundamental to ensuring that each member of our community has an opportunity to thrive, lead others, and be a person of impact. By embracing our differences as a community, our approach to diversity, equity, and inclusion fosters an inclusive, welcoming, supportive, and healthy school culture that promotes genuine respect and acceptance of all members of our community. We are committed to equal opportunity for all persons and do not tolerate discrimination and harassment on any basis.

In 2000, a group of student leaders came up with the idea of creating an Honor Code for Maclay.  After meeting with faculty and administration and researching Honor Codes from other schools and colleges, the Maclay Honor Code was instituted in the Upper School, in which students wrote at the end of each test, declaring their work was honest and complete.

In 2015, a group of students and faculty revised the Honor Code to carry a more straightforward meaning that all students, K-12, could understand and follow.  Each September, the traditional formal ceremony for Upper School students is held, and all new students and new teachers sign a roll book to indicate their participation in the Maclay Honor Code system. The Honor Code Book has become a part of Maclay's tradition and is displayed in our library for future generations to see.