I’m Marcel den Hartog, born in 1977. I see myself as an adventurer and explorer. Together with my wife, Atie, I live by the beautiful river Linge in Leerdam, where we enjoy the peace, the nature, and our shared passion for travel.

The name ISEMI is derived from an ancient Greek word meaning “intimate knowing.” Our purpose is to guide people into a deeper connection with the Divine within themselves and within the cosmos. In doing so, you align your personal reality with a greater reality—and learn to become a harmonious co-creator within the larger order of life.

Our mission is to support people in shaping their own mastery. We do this through experiential learning: starting from concrete experiences and gradually moving deeper toward the core of who you are—as a person and as a professional. For anyone who wants to grow within their field. This way, you live closer to your full potential, carry more responsibility, and experience more meaning in what you do.

We envision a world in which more and more people—like you—have the courage to follow their heart and the dedication to shape that professionally. This means connecting yourself to something greater than you are—not by losing yourself, but by individuating: becoming who you truly are, and serving from that place. It calls for depth in your personal development. Because to guide others toward autonomy and success, you need both self-knowledge and a broader professional perspective.

Mastery is an ongoing process of self-realisation. You create a congruent reality that aligns with who you are at your core—and that contributes to a greater whole. From that embodied autonomy, you create the context and conditions in which others can develop their autonomy and potential—so that personal growth and collective meaning reinforce one another.

At ISEMI Opleidingen, you shape your own mastery. You bring your qualities into the world, look beyond the boundaries of your field, and explore the ecology of your actions. By following your heart and continuing to learn with a growth mindset, you develop the wisdom, autonomy, and love to guide ever larger processes of change. In this way, you become an inspiring leader who brings out the best in yourself and in others.

You develop continuity of consciousness: a stable awareness of who you essentially are, which supports your choices and actions across a wide range of situations. You experience this as a quiet inner strength that flows through your life and gives direction to what you do. In this way, you connect personal growth with professional impact; you take responsibility without losing yourself and act with clarity, compassion, and steadiness. As you mature in mastery, your inner core and your daily actions align more and more. What matters to you, you live.

The effect: more calm in your decisions, more space in your relationships, and tangible results in performance, collaboration, and wellbeing—while experiencing deeper meaning in what you do, for yourself and for the people around you.

Join ISEMI Opleidingen and discover how you can turn your passion into a meaningful professional practice.